I still maintain people expect VTTs to do more mechanical lifting for them than is necessary.
I actually find this very useful.
You can load up mods in Foundry to do all that heavy lifting or you can run it with almost no mods and do all that math on your own.
What I love about Foundry is that once I got all the mods I wanted in place, I barely have to think of the numbers in PF2E at all. Persistent stuff, flat-footed, conditions, weird modifier for bizzare action X, and so on - if you need to figure out, there's a mod for that which will do it for you.
For me, that's a major selling point. The table can focus on the play of the game, and not working out the numbers.
In two games I've been in of late. One GM had mods to automate everything and the other did not. It typically cuts the time it takes to resolve a turn of combat by more than half to have all that automation. For me, as a former 'Champions Forever GM' - that is a massive selling point. And see the impact even in a light and fast game like PF2E, it's a thing of beauty.
That said. When you get a new mod, load up your copy of Foundry on a test world with some test characters and TEST THAT MOD out to be sure it's correct and learn what it forgets to handle, if anything.
The Mods are great tools, but they are not always 103% accurate. I've yet to see one be actually wrong on the rules. But I have seen them not know how to handle that one very weird situation that never happens in anyone's game except of course... the one I'm playing in because a player took that one weird ancestry / class / feat / item / action that the mod author didn't think people ever took.
I have also found a bug or two that, when I took it the authors of that content, was told "yeah we know about that, we've not been able to figure out how to fix it, but we figured it was harmless so didn't think it was worth telling anyone or having any documentation on or even putting out a request for help to find a solution for..."
So just test your stuff out, know the limits. For the vast majority of things it does, Foundry is amazing. Also be prepared for everything to break on updates. So... don't update in mid game. You can update mods, but the base foundry software can blow up all your stuff if you update. For me, it's flat out killed game saves by corrupting the files with the recent move from 10 to 11. Good thing those were all test worlds and not live games where I'd have to tell players to re-import their PCs.