Definitely! I suppose your mileage may vary with tumblr, which I think really hinges on finding the right blogs/communities to follow. I really dislike Instagram in that there is so much reposting. I don't care if there is credit, if the artist/author said no reposting, that means no reposting...Sure, it happens on tumblr too, but at least tumblr has a reblog feature.
I use tumblr daily
following various fandom people and a lot of artists, and I follow webcomics there too. A lot of webcomics are posted there, and sometimes it's an easy way for me to subscribe.
My mostly-writing-ish tumblr is http://bafflinghaze.tumblr.com