I want to handicap my hotspot speed to disincentivize people from streaming videos from my hotspot. I don't want to block the sites per se, so firewall is a no go. I just need to limit their maximum speed.
Limiting hotspot speed is not a function of Windows 11 hotspot (or 10 or earlier).
You need a hotspot that includes that kind of functionality. Most ordinary hotspots do not.
See if there is a limit on how many people can connect. I am not certain about that.
See if you can determine offenders, change the password and do not let offenders in. This is probably the best approach for an ad hoc hotspot.