eeeps

Disclaimer: I work for Cloudinary. But: all of the services that you mention have an awful lot to offer, over roll-your-own solutions. Reliability and scalability, sure — but also, right now, just flat-out-better performance and output. From big flashy features like automatic optimization using perceptual metrics and on-the-fly responsive resizing with Client Hints ... all the way down to nitty gritty stuff that doesn’t get press releases like, say, dialed-in custom resizing algorithms... in 2017, hosted, paid services can do a lot more a lot better than anything you can set up yourself using free tools.

Images are complicated and important enough that I don't see that changing any time soon.