I think having a browser managed by one of the most powerful company in the world is the core of the issue, albeit in indirect ways.
I have no insight into Firefox' technical foundations, but to your point I've been using it since the IE days and never had critical performance issues or compelling reasons to use another browser short of company specific sites: Google properties is one: while Firefox works, Google has obviously no incentive to make it work better than Chrome, and potentially incentives for the opposite.
Companies' internal sites and tools are another: fixating on one specific browser has been an (unwise) long lasting trend, and for a company Chrome being backed by Google has a lot more appeal than Firefox. That was the same dynamic that cemented IE6 in it's position.
Perhaps Firefox missed the V8/electron train that would have made it in the same position as Linux: a platform to run other things on. But I don't know the history around that.
I have no insight into Firefox' technical foundations, but to your point I've been using it since the IE days and never had critical performance issues or compelling reasons to use another browser short of company specific sites: Google properties is one: while Firefox works, Google has obviously no incentive to make it work better than Chrome, and potentially incentives for the opposite.
Companies' internal sites and tools are another: fixating on one specific browser has been an (unwise) long lasting trend, and for a company Chrome being backed by Google has a lot more appeal than Firefox. That was the same dynamic that cemented IE6 in it's position.
Perhaps Firefox missed the V8/electron train that would have made it in the same position as Linux: a platform to run other things on. But I don't know the history around that.