I don't know about Macs, but under iOS/iPadOS you can set a Siri region to somewhere it's unsupported (e.g. Russia) to truly disable it.
It gets back about 15 gigabytes of storage and removes additional stuffs you couldn't disable by setting Screen Time options, such as the Safari Reader's gigantic "summarize" button.
It gets back about 15 gigabytes of storage and removes additional stuffs you couldn't disable by setting Screen Time options, such as the Safari Reader's gigantic "summarize" button.