Hive ended up being the one I landed on after trying Google Vision first (https://cloud.google.com/vision).
The other one I was looking at is Clarity.ai but I didn't get a chance to try that one yet.
This started as a little demo project with Nextjs + Mux and then evolved into more of an actual product (https://github.com/muxinc/stream.new).
Right now the lightweight utility aspect of stream.new feel right, but if we continue to build upon it as a standalone free product then adding the concept of an "account" with saved videos makes a ton of sense.
* Child porn and similar content that is a level beyond simply "NSFW"
* Uploaders of NSFW stuff are always in need of a new platform they haven't been kicked off yet, and newer platforms are likely to be dominated with this type of content. Unless you want your platform to gain a reputation as the place for mostly NFSW content, you probably don't want this.
* Porn is almost always posted in violation of copyright.
* Hosting porn opens you up to legal issues if you can't verify that everyone involved is adult and consenting.
* Payment processors, hosting companies and other service providers you rely on usually have strict policies excluding porn.
And that's just addressing legal pornography, not other "NSFW" content like child abuse, animal abuse, general violence or gore. If you run a large enough public user generated content service people will use it to distribute illegal content or flood it with jihadist execution videos to ruin someone's day.
If a site is specifically intended as, or is incidentally used in the course of, professional work, then NSFW content can literally get your users fired if overseen, logged, or otherwise detected.
That turns out to shift your user demographics in the medium-to-longer term, and not in a direction that's generally compatible with high-quality and engaging content and interactions.
Where NSFW content is permitted, it should be specifically tagged as such, and not presented unless users specifically opt in to it.