Considering changes in communication, where mail is less relevant compared to discord, slack, WhatsApp, ... I guess many people can meanwhile live quite some time without looking at a mail app at all. While browser is needed regularly.

Indeed, browsers are open a lot. It's nice to consolidate your needs to just tabs in there. I use Slack and plenty of other things that way too.

I will say, however, a proper email client is nice for archival purposes.

(note: not the person you're replying to, just a random passerby)