You owe a massive amount of your economic output to others because you stand on the shoulders of people who are standing on the shoulders of people who are standing on the shoulders of people... and it's not a simple pyramid, but one giant ball of interdependence that will be thrown into chaos if a critical mass of people try to buck off their riders.
You can't pay the guy specifically holding you up, and not anyone else, because no one can truly identify their keystone supporters. So you pay a bunch of free riders, too, because that's the only way to ensure your supporters stay happy enough to carry you. And they may think that you aren't outputting anything of value to them, and they only carry you because they can't tell who's throwing all the bread down from above.
I pay freeloaders, because I don't want to fall off the ball, onto my fat ass, and fend for myself, using only what I had on hand when I dropped.
If someone engineered a more efficient society, where everyone has a useful and necessary role, for which they each have an individual advantage, and waste is unsupportable--such as for bootstrapping an off-Earth colony--I might join that, but then still accept that I will implicitly be supporting future generations of freeloaders by accumulating capital that will outlast me.
You don't want an accounting on what you are truly worth to society at large. Trust me.
Ok, fine, but if taxes get high enough, along with the benefits, you can expect some people to stop caring and start becoming freeloaders themselves.
Don't be surprised when people just say "screw it, this isn't worth it anymore, I am going to become a freeloader myself".
Some people yes. Good riddance from productivity to them.
The people with actual internal motivation would do inventions, great work, art, programming, etc, even if they're not getting mega-rich from it.
It might slow the speed of mega-corps and new gadgets every month, but perhaps that's just what the doctor ordered. More quality, less greedy obsolescence, longer term products, more personal vision (as opposed quick-buck-schemes).