Maxroll has updated a lot of their build/class tier lists. While I laugh at most of the youtubers, I do recommend Wudijo. He's very knowledgeable and behind a lot of the maxroll guides.
The #1 thing is that we don't have all the patch note details yet on certain nerfs. Also, there's always something that ends up being bugged and being way more powerful than intended, so these things always changed.
For those new to seasons, you just start out with a leveling build anyway, by the time you get to endgame, they'll have the endgame builds fleshed out more.
Another thing to keep in mind is that the "S tier" builds are often the ones that will catch early nerfs. They are sometimes inconsistent with their balancing so an S tier build can get nerfed and suddenly drop.