The argument is a familiar one that has been hashed out several times in other threads and boards and is constituent of the well known "scaling problem" as its called. Except in this case, it is the security at debate here. Miners not getting paid enough rewards in transaction fees so either the price of bitcoin must double constantly or the hashrate crashes massively as miners quit and makes attacking nodes feasible
They claim a security problem due to the risk of 51% attacks making the price fall
Changing the supply schedule is not related to the scaling issue. The scaling issue is driven by the decentralization design ...
- There must be a substantial delay between blocks, so that all the nodes are able to remain synchronized
- The block size must be limited, so that it is affordable to run a node
These limits - 600 seconds and 4 million weight units - determine how many transactions can be processed per day
The supply limit is very, very high (2.1 quadrillion money units) so is not relevant to scaling