Thus the reason why I gave up on subscribing to newsletters in my inbox
long ago and use https://kill-the-newsletter.com to turn them into
feeds. Also being able to use quick navigation is much more efficient,
and I use Thunderbird for my regular email. therefore, I wouldn't
recommend using email as an RSs reader anytime soon..

   Sure you can use the web client, but over time, you're going to end
up with lots of emails if you don't keep up with it. To me that's what
an RSS reader is for. I may not want 359000 emails, but that's how many
unread items I have in my feed reader. part of the purpose of an RSS
reader is an archive, so that really doesn't bother me much.