I have the feeling, that i'm still having a similar amount of fun/happiness when i do my current job vs. my previous job but with more money.

More money means for me: less working later or nicer things now or faster/more stability & safety.

I have also seen enough people being afraid of quitting, people unable to quit, people who did not pull their weight, still complaining, still not quitting.

I have seen people not pulling their weight and being able to find a new/better job where they will still perform the same now just another company doesn't know what to do with them and just having them.