Google is paying, and yes, you can, but they will disconnect you after a while. And if you abuse it too much, you won't be able to use it until the following day...
You can also buy Colab Pro and Colab Pro+, which have fewer limitations and faster GPUs.
In my usage Colab and Colab Pro were similar, with plain Colab occasionally OOMing during model loading. That said I've actually been seeing times slower than yours on Colab and I think they're slower than on my RTX 3080. ~15 secs per image. I'm not sure why, though.
You are much better off running it locally at those speeds. P100 does 13 to 33 seconds a batch in my experience. Cloud to cloud data transfer (Hugginface to Colab) is ridiculously fast tho.
I'm on Colab Pro and get about 3 steps per second when generating a single 512x512 image at a time, with slight throughput improvement when I batch 2-3 images
Yup, totally free (with a Google account). It's run as a learning resource and there's an upsell to Collab+ and Collab Pro, but for running StableDiffusion it makes it very easy to get started!
I think it's less of an upsell and more of a data collection and a market positioning. Google would like to, for example:
1. Be central in the machine learning ecosystem. This has broad ripple effects, such as recruiting.
2. Doing things there means Google can track how you use machine learning. This can be used for everything from understanding trends in machine learning, to, again, robustly identifying individuals for recruiting efforts.
It seems like the cost is nominal at Google scale for what Google is getting. I suspect the pricing for the higher-end services is less a money-making scheme, as at some point, free is no longer sustainable (and if unlimited CPU were free, that would be prone to abuse / misuse / overuse / wasteful use). The amount of money Google makes there is nominal at Google scale.
