[nolok]

It really doesn't apply with PHP though. I mean that.

Nowaday you use composer so your versionning and compatibility is done for you, everything is made out of libraries instead of monolithic bloc, and no major libraries use anything below PHP 7.X

I don't think you can find any sort-of-major library that doesn't work on PHP 8, nor anything with any kind of serious usage that isn't working on PHP 7. That's sort of the point of PHP making sure backward compatibility remains.

And if you mean "but my code can't use the good stuff", actually nothing stops it, even the type system stictness is decided caller side, specifically to avoid the issue you mention.