Why won’t miners support a fork that increases the total supply of bitcoin to maintain block subsidies? I feel like its because it hurts the main value proposition of the thing they are mining, but is there anything else that might dissuade miners from a move
like this in the future?
No. There will only ever be 21 million
This idea comes from greed.
Miners shouldn't go into so much debt to mine.
The problem is these miners are greedy taking out massive loans to mine
So no there will only ever be 21 million
Some miners may do so, but I doubt any other participants in the network would favor such an action. The separatist miners would then likely move to mining on a forked chain like we saw in 2018. The original chain would see a drop in hash-power for a little while until new members begin mining on the original chain and bring it back to a happy equilibrium. The new fork will then be forced to compete head to head with the original and lose due to the substantial head start of the original Bitcoin. Most fork miners would then move back to the original or go bankrupt.
