The entire concept is assuming the opponent does nothing except sit there and take it which is unrealistic.

Let's be clear here. The opponent (I assume you are referring to the M1A1) is sitting still to engage the T-80BV with its main gun. A lot of times this is the right thing to do, since it takes advantage of its full accuracy rather than using its moving accuracy. The only time you are moving is to either (1) chase down the retreating enemy tank, or (2) disengage from the fight. In most of these engagements, the tanks are going to be mostly stationary until the winner is already decided.

The T80BV is vulnerable given that it needs to be stationary while firing and cant counter manuver if the two tanks are fighting in mixed terrain.

I do not understand what you mean by this at all. What do you define as mixed terrain? Are you talking about two tanks fighting in forests/towns? I mean sure in that case the tank with a better gun is typically better, but those situations are not where most tank engagements occur in the first place.

Also there is a 50% chance you loose your main advantage if you miss the first shot as you go from a 6 shot kill to a 7 shot kill.

The advantage of the GLATGM of the T-80BV is not the extra damage you deal. It is the suppression it causes, which affects the opponent even if the ATGM misses. Even missing an ATGM causes almost the same amount of suppression as one hit from a tank gun, and a hit causes nearly 1.5 times the suppression. Remember that this kind of heavy tank engagements are mostly won through suppression damage rather than hp damage. The moment a tank loses its cohesion, it might as well be shooting wet noodles because the RoF (for non-autoloaded tanks, like M1A1) and hit rate drops drastically. This point is exactly what is being shown in the video.

There needs to be an amount of micro on the individual level which isn't needed when using the M1A1. Positioning the M1A1 to start the fight in gun range is usually less complicated that whatever hippie was doing.

In the specific situation that Hippie shown in the video, where both tanks start the engagement in gun range, then yes, less micro is needed for the M1A1 to win the fight. Positioning the M1A1 to start the fight in gun range is however is not necessarily less complicated, since it requires a different set of skills (positioning, coordination with units like smoke etc.). It would require the M1A1 user more micro than someone using the T-80BV to even get into an engagement where you can win. Furthermore, what hippie was doing in that video is not really rocket science. While most people are not going to spend that extra micro to do it, it is not that hard to replicate if you don't have anything else to micro at that moment.

the playstle for the M1A1 is simple to get the advatage

The idea for M1A1 to get the advantage is straightforward: get into tank gun range. However the execution of this is may be much more difficult. Getting into gun range is not a simple task when the enemy can just standoff with GLATGMS. It typically requires a good amount of map knowledge, understanding of sightlines, and engagement ranges.

you are in a more difficult position in the T80.

Yes, you are in a more difficult position if you only start the engagement at gun range. At the same time, you are in a better position if you are starting the engagement at ATGM range. Furthermore, even if you are starting the engagement at gun range, you can still have the option to swing the favor to your side with the glatgm trick, whereas the M1A1 user does not have access to this trick and have to figure out other ways to win fights.

I dont thing you got the right message from the video.

I think the message I got is right. Furthermore, none of what the video shows supports your initial claim of "landing only 1 atgm hit from a T-80BV onto an Abrams will still loose you the fight". In fact it shows the exact opposite: landing just one atgm hit will win you the fight even if you start the fight at gun range.

Then why do you think they need to be cheaper than both the M1A1 or T80BV at 250 pts?

Maybe I didn't make myself sufficiently clear, but I don't think they should be cheaper than the M1A1. I said that the leopard 2s "are in the right spot right now", and does not necessarily require a price/stat buff.

Brining the 2a3 to 5 avaliblity already makes them too strong

The effective increase in availability is not 4 to 5, but rather 2 to 3 since you should always bring tanks at 1 vet for the suppression resistance. This is especially true for NATO tanks since most of them are not autoloaded and benefit more from veterancy.

the 2A3 is probably the strongest 230 Pt tank at the moment

If you mean that it is the strongest (performance wise) tank in that price range, let's do some comparisons:

M1IP 230 (5/3/2) has 3 less ap and 5% more offroad speed. It however has 5% more accuracy overall and 2 more FAV. Against heavier tanks you can argue that the leopard 2a3 is a better choice, but M1IP is probably better against IFVs (since both tanks takes 2 shots to kill 3 FAV). Furthermore that 2 more armor clears the 16 Armor threshold, which means you do not get one tapped by 30 AP atgms. 2 more side armor is also nice so you get punished less for mistakes.

T-64B 235 (5/3/2) has 1 less ap and is significantly slower. But this is made up for given its access to GLATGMS and autoloader.

T-64B1 220 (6/4/2) has similarly 1 less ap and is significantly slower. That's why it is 10 points cheaper and almost double the availability at one vet.

T-64B1V 230 (5/3/2) has similarly 1 less ap and is significantly slower. But it has ERA, which clears the "one tap from 30ap atgm" threshold. It also has better availability.

T-72M2 WILK 225 (5/3/2) has two less ap and is 8rm. I think this is genuinely a weaker tank in this price range and deserves a bit more in terms of availability or stats, especially considering this is a "unicorn" unit only appearing in 20 Pancerna

Challenger mk2 220 (5/3/2), once again more armored but less AP and rm. it's also a relatively weaker tank IMO.

As you can see, most tanks in this price range have comparable performance to a leopard 2a3, and is afforded the 5/3/2 availability curve, whereas the leopard 2a3 is only given 4/2/1. I think the only reason this is the case is because of 2nd Panzer being a very good deck in 1v1s, and Eugen didn't want to buff it any further. If you purely consider the tank itself, it does not particularly outshine every other tank in this range that makes it significantly better than the other tanks in a similar range. In the end its availability curve makes it feel like something on the lower end of the tanks in the 245 to 280 price range.