My Samsung A40 has a toggle called "OEM unlocking - Allow the bootloader to be unlocked". That's in the developer options. My previous phone from Sony had the same option. If Apple wanted they could do the same.

Security loopholes are a different thing.

They prevent jailbreaking by not providing a way to do it.

They additionally prevent jailbreaking by patching vulnerabilities.

Only one of these things is being called out.

You can get into all sorts of theoretical discussions about how if there was a way to do it, they'd be increasing their attack surface since now they have to make sure this path is locked properly when the user doesn't want it, but people act like the only way for jailbreaking to work is for Apple to stop patching 0 days, which is not the case.

Meh. If the file system weren’t encrypted I’d agree with you. Now that it is we should be allowed to replace the OS.