That's my experience too. I transcode a lot of video for a personal project and hardware acceleration isn't much faster. I figure that's because on CPU I can max out my 12 cores.
The file size is also problematic I've had hardware encodes twice as large as the same video encoded with CPU.
I would SO love it ! I regularly take a look at the existing offerings, and there's a few options for "transcode video as API". However it's pretty costly, i regularly have batches of videos that would set me back 30 to 80 bucks if i were to transcode them in the cloud. I don't think it can be done at any price point i'd be happy with for this kind of personal project - especially considering that the alternative is just to max out my CPU for a day or two.
Well it wouldn't be hard at all to make a POC for yourself. You could make an open source project to automate it all. I suggest using hetzner (cloud) because of the price.
You just need to use the hetzner API's to put all your video on a shared drive, write a simple job runner in whatever language you like or even simpler you could write your commands in a text file on the shared drive. Write a simple script to mount the shared drive, look for the job file on machine startup; then have your machine delete itself via hetzner API. Email yourself before that. There, you have your weekend project.
Thanks for that datapoint, I was a little bummed to see ffmpeg not using any of my Macs GPUs, but the CPUs ain’t no slouch so I’ll just go with software encoding on Mac