These are not table stakes features for usability, especially the last one. I use Arc Browser and while I think vertical tabs is nice, this is not a MVP feature

These are not table stakes features for usability, especially the last one. I use Arc Browser and while I think vertical tabs is nice, this is not a MVP feature. Additionally, I'd argue Multi Account Containers + Total Suspender are not either. Even MAC doesn't come by default w/ Firefox, you still need to install it. I'm willing to bit the vast majority of internet users still don't know about it. And Total Suspender is really a response to RAM use by browsers. It's a great idea, browsers should implement it, but many people still don't know about it and it's not necessarily a deal-breaker.