Sure it's easy...

But for a company it's almost always cheaper to pay for the service. That way you don't have to deal with maintenance, setting up redundancy, mirroring, etc.

That said, aws, google and quay are all competitors in this space.

It's pretty easy to just pay, I'll give you that.

For an example of just how good their image is:

I set my companies up almost a year ago, had to deal with it about once.

The docs cover a HA setup (if you really need it - most won't), data backups aren't really needed if you're using a storage backing, and I just use local file system - absolute worst case I have to wait half an hour to rebuild and push everything.

The downside risk of running your own is very low. The upside is a few bucks and you have your own private registry local to your network.

Just as a small note, data backup isn't just for hardware or service failure, it's also for ooops I just deleted my bucket. Yes you can rebuild, but that in my case would take quite a few days and money in compute. That having been said hosted services are actually worse in protecting your self from user error...