(fallen london stamps by I've also seen https://mltshp.com/ posted around elsewhere, which seems at first glance to be an Instagram meets Pinterest kinda deal. It's also indie and ad-free, with the caveat that to post, you need a membership, which starts at 3 USD per year. (note: year, not month!)
I probably will not join because there are Numbers, it's images-focused, and I feel kind of iffy about the whole concept of reposting pictures, but I thought I'd toss it out there so folks have options!