My webmail solution of choice, for quite a few years now, has been Fastmail. Their interface / design / ergonomics are lightweight, responsive, efficient and -- in my view -- Just Work. (They were owned by Opera for a while, largely I think because of their massive levels of expertise in making mail fast, simple and efficient, but are independent again now.)
So my various email addresses -- gmail, yahoo, outlook, so forth -- are all fetched from their providers into Fastmail (which also allows me to set aliases to the addresses I own so I don't have to interact with anything I don't enjoy interacting with!)
The downside: although there IS a free offering, you'll probably want one or other of their paid accounts.
The web end is good, they support several forms of 2FA if that's your thing (I have a yubico key but they have several other alternatives) there are mobile apps too... I don't evangelise them as much as I should but I've tried a lot of webmail solutions over the years and nothing else comes close.
And does it matter which browser you use? Apparently not. Fastmail lives up to its name, generally.