Yeah, cross language is generally considered "a protocol", and exists only to cross process boundaries. That's definitely useful! It's even a mostly reasonable one (though with a few weird decisions either due to blindly copying Prometheus' flaws or due to... idk avoiding copying Prometheus on principle? Very strange sometimes, but livable). We needed a grand unification here, even if mediocre, and the time was right.
Trying to make all the supported languages feel similar (beyond sharing concepts which almost directly match the protocol) is foolish in the extreme, and it's why it's such a monstrosity. And worse, they seem to treat that as more important than the bottom-most clients that speak the protocol, so you might be waiting years for any support for a third of the system!