Simulacrum has no idea what he is talking about.
If he "gimped" himself thats because he is a lousy player that expects whatever he does to work as well as a focused build and dish out damage at same levels.
While he completely fails to understand what jack of all trades are actually good with.
Ive seen him post that rubbish as if its gospel in other threads too, because he expects wrong things and cant figure out whats what and then just wants to make sure everyone understand how "bad the game is".


Jack of all trades work exceptionally well in this game since it is made for such builds.
Despite those preset builds in Character creation screen.

With hybrid build you of course trade between being very good at a single thing to being very diverse and having more options.

It is better to start like that from the start and adapt your playstyle and attribute-talent building to it.

here is a tip:

If you want a really good fighter-mage kind of a build go for Man at arms and Air magic skills.