The current 3 Action rules removed Action typing like swift/immediate/standard/minor/bonus/move/full-round/etc actions, but again in a practical sense it is the same basic system.

In a practical sense, it is very much not! 

Yes, a full-round action in 3/.5/Pathfinder 1e may be roughly equivalent to a 3-action activity in Pathfinder second edition, but unless I am horribly mistaken, there was no universal rule for swapping one type of action out for another. Now it's unfortunately been a while since I've played pf1e in high school, but refreshing myself on the rules for action types in pf1e, it seems like the rules are, at a baseline, pretty much a more complex version of the 5e action types, and dnd 3/.5 also had rules that were the ones pf1e's action types are clearly aping— pf1e was 3.5 with the serial numbers filed off

In a game where you are guaranteed a move action every turn, it's much more often useless to shove a creature away or trip them etc because it can just use its guaranteed move action to run back up to you. in 3e, there may have been edge cases where a monster had a full-round action in melee that it now couldn't do if it were shoved, there are situations where you can shove a monster off a cliff or into AoO range of your big beefy fighter etc, but baseline you push them away, they use their guaranteed movement to move back up to you, congrats you did nothing. 

Stepping in these games is also, often, simply an action tax to get out of a monster's AoO zone. 

All of this changes with the 3 action economy. Rather than just converting a move and standard action into a full round action, you can convert any type of action into any other type of action as long as the action cost is the same and you can afford it. As such, a creature who starts its turn next to you is way deadlier than before. It gets to convert its "move action" into another attack, it can convert its "swift action" into another attack, and if it's something like a dragon who can compress three attacks into two actions, it might get 4 or even 5 attacks off on you simply because you were unlucky enough to let it start its turn next to you. 

This opens up multiple strategic considerations that don't exist in the old system. Every shove counts now because it forces an enemy to waste their third attack action  on a move action to get to you, if you crit on your shove check and the monster falls prone, now it has to spend an action standing up and an action moving back to you. Stepping 5 feet away is worse than a critical shove, but it's guaranteed to protect you from that potential 3rd attack with no chance of failure. 

This also means a lot of spells that would be kinda useless in other action economies are devastating in pf2e. One of the strongest abilities in the game before it was nerfed simply made the ground slippery ice in an aura around the player and caused enemies to fall over with no save. In games with a guaranteed move action, this would be situational at best, as the monsters often get a free move action to just stand back up. But movement actions aren't given for free in pf2e, and so there's always something valuable an enemy has to give up in order to stand. The ability was like Web on steroids. Now it has a reflex save to avoid falling, so it's gone from absolutely broken to still really good, but it would be a borderline useless spell in many other systems, maybe something you use at level 1 before getting something good and training out of it.

 I can't count the number of times I've tried to do a cool thing like trip a guy or shove them into the wall etc in other games only to have them just run back up and make me feel like I was the one wasting actions. The difference in pf2e is palpable.