It is not correct that a soft fork (same as segwit or taproot)
“changes the permissionless nature of Bitcoin”
Bitcoin is a system of rules, that anyone can use for peer to peer digital cash permissionlessly- but you cannot break the rules without ending up on your own hard fork with a worthless token. The rules are based originally on Satoshi’s design in the whitepaper, and they are updated according to network consensus over time.
In general, Bitcoin is based on restricting things- you cannot send the same Bitcoin twice, and the amount of Bitcoin is never more than 21 million coins for example.
This softfork in theory is not flawed, and does not require a “gatekeeper” it is a proposal to change consensus, limiting the amount of abritrary data.
It can be implemented similar to the UASF during the block size war.