I really wonder what you are basing this opinion on. The most recent stable release (Oxygen) was released last June, and Eclipse Che, their cloud IDE last October. In Stack Overflow's 2017 Developer 2017, 20% of Web Developers use Eclipse, 25% of Desktop developers use Eclipse, 22% of SysAdmins use Eclipse, and 27% of Data Scientists and Engineers use Eclipse.

10 years ago everyone at my startup used emacs or vi.

Today those same engineers still use emacs or vi.

Did I miss something?

I don't even know any C++ programmers who thought Eclipse was a good editor, let alone the best.

That Eclipse is now pretty much gone only strengthens that position.