Only reason I still have prime is simple - diapers. I save enough on them alone to justify it. But once that's done (another year-ish), I don't think it will be worth it anymore.
And yet, I still don't use prime video. It's just not a good experience, and obviously getting worse. And as I have kids, the management of what I'm ok with them seeing is way easier on JF than prime video.
Only makes it worse to remember that Amazon killed diapers.com by selling under cost until they couldn't hold on any more and more we're all worse off.
Why not Costco instead? It's $65 for a year, and you'd probably make that up on diapers alone in that first year. You need to actually go pick them up so it wouldn't work if you don't live near a Costco.
There are also other bulk stores as well, depending on your area. Look around, Amazon is rarely the best price, they're just the most convenient since they have pretty much everything.