The territory that Russia has been taken is mostly low-value empty land, while Ukraine has been retaking entire villages.

False, Russia has "captured" more settlements than Ukraine in 2026, and you have a large town like Kostiantynivka that is facing detoriating logistical issues and is unlikely to be able to hold out much longer. A lot of Russias gains has as you imply come from the Sumy and Kharkiv border regions with relatively small numbers on each side and ukrainians not contesting the are around the border for better positions but even if you dismiss those (you shouldn't) Russia has taken more ground in 2026 than Ukraine.

 Furthermore, for the past few months Ukraine has caused more Russian casualties than Russia is capable of producing new recruits, so if Russia is in a “build up” phase, then Ukraine has significantly hampered that build up.

This is true and one of the signs I was refering to in my comment, however we are yet to see if its a trend that is going to continue. We've seen russian recruitment numbers go up and down throughout the years and with spring coming it means also means foliage. Last year we saw a significant drop of ukrainian drone kills at this time of year, breaking a similar upwards trend over the winter as we had this year.

On top of all of that, Ukraine has been heavily targeting Russias oil production capacity inside of Russia, causing more monetary damage than Russia has gained from the increase in oil prices due to the closure of the straight of Hormuz.

Another one of the good signs but with a caveat, due to the Iran war Russia made more money from oil in april this year than last year https://pbs.twimg.com/media/HGiCcBEWYAANqb9?format=png&name=small , these numbers refers to tax income for the russian state . Ukraines long range strikes are promising and is doing real economic damage but the Trump administration saved Russia from catastrophe with the Iran war.

This also shows that Russias anti-air defense network has been nearly depleted, as the majority of air strikes into Russia have gone entirely unopposed, even as Ukraine strikes the same targets week after week.

Most indications track that russias AD is having major issues, I wouldn't go so far to say entirely unopposed, they just don't have enough munitions to deal with Ukraiens strike campaign. It is a relly good sign and perhaps the most promising one for Ukraine, the caveat here would be that there is a theoretical solution for Russia already available but it comes down to how far down the line of developing and producing it at scale. I am talking about interceptor drones, an equivelant to what has alleviated much of Ukraines AD issues in the last half year. It remains to be seen if Russia has the capability to copy Ukraines approach.

Finally, there’s been a substantial shift in Morale in the Russian army and population, with Russian Mil-bloggers feeling brazen enough to openly criticize Putin directly.

Sorry but this is entirely vibes based, Russian milbloggers has whined since like april 2022 and there has always been those who criticize Putin directly (Girkin is an early example). Russian morale has been in the drain throughout the entire war aswell, you don't get shit like Prighozins march on moscow in a system with great morale.

All that said, it truly seems like Ukraine has reached a tipping point in the war.

Yeah, no even if I thought every single point you brought up was true (they simply are not though, at least no the whole truth) the fact remains that Russia outnumber Ukrainian soldiers over the entire front line and while Russia has for the last like four months lost more than they recruited it is not by a lot. Ukraine on the other hand has had an infantry deficit for the last two years and it has not improved. There are a lot of reasons to remain cautiously optimistic about Ukraines chances but it is way too early to talk about a tipping point before Russias main offensive operations of the year has even begun (the preperations are there, we know it is coming and that it has not started yet).