For an application like a build server, the only metric that really matters is total integer compute per dollar and per watt. When I compile e.g a Yocto project, I don't care whether a single core compiles a single C file in a millisecond or a minute; I care how fast the whole machine compiles what's probably hundred thousands of source files. If E-cores gives me more compute per dollar and watt than P-cores, give me E-cores.

Of course, having fewer faster cores does have the benefit that you require less RAM... Not a big deal before, you could get 512GB or 1TB of RAM fairly cheap, but these days it might actually matter? But then at the same time, if two E-cores are more powerful than one hyperthreaded P-core, maybe you actually save RAM by using E-cores? Hyperthreading is, after all, only a benefit if you spawn one compiler process per CPU thread rather than per core.

EDIT: Why in the world would someone downvote this perspective? I'm not even mad, just confused