A web browser is a viewing portal to a specific page, accessed upon request

A relay is a stream of stuff you then have to filter

It's really like apples and oranges, web pages or blog sites is probably a better thing to ask about than web browsers

a specific page is also stream of stuff you then have to filter

if I bend over backwards far enough, sure, I can see how it can look like that

A relay is more like page updates across all of the internet being event streamed