Right now, it's pretty easy to get a few A/H100s (Lambda is great for this), but very hard to get more than 24 at a reasonable price ($~2 an hour). One often needs to put up a 6+ month commitment, even when they may only want to run their H100s for an 8 hour training run.
It's the right business decision for GPU brokers to do long term reservations and so on, and we might do so too if we were in their shoes. But we're not in their shoes and have a very different goal: arm the rebels! Let someone who isn't BigCorp train a model!