There’s always meaningful choice no matter how a skill system is structured (you’ll just clear lower difficulty maps with your build). What you want is meaningful choice for META build. And there’s no such thing, no matter what skill system is there, there are the online guides with the meta stuff that everyone copy/pastes.
What could be done however is making it extremely hard for the online guides to appear by changing the starting conditions each Season pushing the players to solve the game again (by themselves). Such idea is applied in Hades where you are given limited random options how to improve your build each time you find an item. Could it be done in Diablo?
On theory, yes, it could (although we have to sacrifice the short term competition). On practice, the Diablo player base prefers to copy/paste since it’s the easier thing to do, and they won’t do it in D4, but someone will surely do it in the future (since it serves for way more replayability).
To have what you want in Diablo there needs to be AI involved and the game variables (ALL OF THEM) for each player have to be unique/different each Season from all other players. This means my fireball damage at lv1 would be in the range of 1 to 100 (randomly) each Season. In Season 1 I could get fireball damage 55, you could get 95, but I can get frozen orb 95, and you 55 (there would be still some rules regarding randomization of variables applied done by the AI, so that some players aren’t running super hot, while others run extremely bad). Then my tree would be different than yours, just as my stat range on items, the legendary rolls, everything having a variable… And online guides would be bricked if our game is complex enough (since you’ll lose more time to enter all variables in the online trainer/planner than to play the game yourself). And you’ll have meaningful choice regarding what’s META FOR YOU.