I understand the concern about the extensions/addons changes, but FF is still a distinct browser.
Several things immediately come to mind:
* Mozilla is a more trustworthy company than Google, so all things being equal, I'll take their product.
* Container tabs (or multi-account tabs now) are a killer feature for privacy and greatly improve the "multi profile" use case
* Firefox Mobile allows extensions, where Chrome doesn't support it.
The only negative for me with FF is that in the enterprise, FF Kerberos/SSO function seems inferior to Chrome, which "just works".
But for it being closed source, I think Vivaldi is a better experience than Chrome. Sure it's "just" a reskin, but point is, Chrome is in 3rd place in my opinion.