Chromium isn't successful because of the billions thrown at it. It's successful because it was significantly better than anything else during its rise:
It was significantly faster than IE and FF. Much better memory management and crash handling via separate processes. Strict adherence to web standards. Seamless auto-updates that required no user intervention - ever. No admin privileges needed for updates. Clean UI that stays out of your way. Top-tier developer tools built-in. Very secure. Has there ever been a widespread instance where users were infected with malware from a Chrome exploit? I haven't heard of one yet.
Any competitor to Chromium needs to be significantly better than it for genuine reasons. Unfortunately, "not Google" and "privacy" aren't going to cut it for most average users to switch over. Unlike Meta, Google's reputation isn't in the trash so people still trust them.