Pools are centralized, but one can switch pools easily.
No one has a "right" to participate. If you have something of value to offer, then it is a permission-less entry, if you have nothing of value to offer, no one should be forced to let you participate at their cost. If you want to mine, earn money and buy miners.
"Well fed is not a friend to one who is hungry."
Russian folk proverb.
If mining is truely centralized the way you described it, the best option would be to decentralize or ban mining completely, otherwise the central forces will move to other things to centralize.
I'd prefer a situation where mining is suspended for the time being and maybe replaced with better alternatives. One of my favorite alternatives is rewarding the new miners with non-financial incentives like points/merits, ranking up in decentralized communities, more privileges etc. The rewards like points should only be used within the bitcoin communities.
I understood your idea. Your idea would be good if it would solve another problem: how to carry out the issue of coins? That is, if we do not issue coins as a reward for block mining, then how to issue them in the economic circulation environment? Who and by what rules will these coins receive? Have you thought about this?
At the moment, Bitcoin is a comprehensive solution that takes into account both technical implementation and economic tasks. In the case of intangible rewards, economic challenges are lost. Therefore, your solution is not comprehensive.