I can imagine that Google is somewhat interested in keeping Firefox alive as an independent browser though, just to ward off monopoly issues.
Yes, there are plenty of Chromium reskins, but Firefox is the only other remaining full, cross-platform browser engine.
I think they were using the funding excuse as a way to cut staff without looking like bad guys. Reality is they were already deep in talks with Google on resigning and did the job cuts before finalizing.
They're probably doomed if the exact correct choices aren't made, I'm in that unpopular crowd that believes they should find a way to graft Firefox's presentation and features on top of Chromium to save on Gecko maintenance costs, and then continue to monetize with side products like their VPN and Rust (consulting). They should sell Pocket.
Marketshare gains will take time, that's a long hard road but it'll be based on features and privacy. If Microsoft couldn't hold off Chromium with EdgeHTML, then a smaller player won't be able to. There's still Webkit if de facto standards are a worry. Mozilla isn't the well-positioned, deep-pocketed player that should be offering choice in the rendering engine market.