They do this by riveting the entire keyboard assembly to the top case. Meaning you can’t just replace the keyboard, you have to replace the entire top case.

As others have already alluded to, drills and self-tapping screws exist, as do replacement keyboards without the top case.

In many other machines, it is common for the factory to use rivets on initial assembly, but to service you drill them out and replace with bolts or screws. This is the expected procedure and even described in the service manual. I actually did this a few weeks ago for an old fan.

I'm advocating for right to repair as anyone else, and not fond of Apple's decisions in general, but this seems like a tempest in a teapot.