I mean, generally what matters is how things scale. This type of slowness is trivially solved with horizontal scaling. Not just that, as a design choice, shared

I mean, generally what matters is how things scale. This type of slowness is trivially solved with horizontal scaling. Not just that, as a design choice, shared-nothing makes horizontal scaling easier. So this type of slowness isn't really the type that matters, and if anything is actually a net benefit at scale. [Unless you are truly latency-critical, but quite frankly that is pretty rare and php would probably not be the best choice for that at any scale]