It blows my mind that no company is currently able to challenge Chrome.
Not even Microsoft or Apple is interested to challenge the status quo.
Mozilla keeps it up because of the principle that there should be more than one decent rendering engine. For-profit companies can't take that stance.
I think that as developers we could be doing more to help with that. Using Firefox, testing with Firefox, avoiding Blink-only APIs, etc...
Also note it's not just Edge we're talking about. Microsoft is one of the main Electron stewards, and products like VSCode are built on that platform.
The benefits to common engine are too high.