In my experience, not only do a lot of sites block access from datacenter/cloud IPs, but you will routinely encounter captcha loops.

This is true, keeps getting worse, but depends heavily on the datacenter/IP.

I've also had online shopping orders flagged or unable to buy at all by doing this. They seem to consider traffic as automatically suspicious when it's not through a residential ISP.

Although with the amount of "compromised" residential hosts these days that are for hire through grey-market proxy dealers, I don't know what to think anymore.

Also true, but also happens in workplaces.

It will be even worse using a normal VPN so no solution there.

Also, if you're signed in it will be fine.