You mean something like Rise of the Tomb Raider which has an experience bar that fills up for doing the most basic tasks? For example, opening a treasure chest or investigating a mural. Then you get one skill point per level up and can apply it to a skill tree.
AAA games are heavily focus-tested and it has been found that filling up bars is an easy way to keep people playing, because filling up a bar in and of itself can already be enough for an addictive personality, so it hardly matters if the game is mediocre or outright sucks. @Ka-pi96 tends to serve as a good example of the cow that the video game industry milks, so it should be easy to understand what I am getting at. AAA gaming is about exploiting all means to make people spend regardless of game quality, hence why experience bars have found their way into many games.
I admit, I choked laughing when you talk about Kapi as an example :P
But anywoo, I think a skill tree or level system needs to give you some freedom of choice to implement the way you wanna play a game that suits yourself but won't give you everything on a silver plate by the end of the journey.
The best example I've seen in a game recently is actually Shin Megami Tensei IV/Apocalypse. Each level you're given 5 points you can distrubute with 5 basic stats. Which means you can build your character towards a specific way of dealing with the battles later on (Physical build, magic build, etc ...). Also you're given 5 App points you can use to purchase "skill tree" abilities, but the catch is that you won't be able to get all of them so you need to make some sacrifices on what you think will be most suited for your playstyle (fusion-er, demon negotiator, expanding you demon slots, skill growth, etc ...).