I am skeptical that Hetzner or OVH or similar could get off the ground starting in 2023.
There are a couple of things working against a boostrapped public cloud:
First, you gotta buy expensive kit. And then hope you can make your money back over the next 18 months.
Funding this is hard. You could try to borrow money, but that (a) increases your underlying cost and (b) dictates how you sell. You can't borrow money against developer usage / traction because banks don't know how to value that. So you have to do top down sales and land some big, committed customers before you can use debt.
The sales model constrains the product. There is no big, committed customer on the planet that will buy global infrastructure from a company who hasn't built it out yet. So you won't be building a global cloud, you'll end up in one region.
And, no big committed customer is going to buy something novel. They do not care that "fly launch" makes it easy for a dev to launch a new project. They care that they got the best possible pricing when they were shopping for their hardware. They might care that they can run k8s on it.
This is all fine, though. I'm not opposed to it. But I think it leaves you with something that's not as good as AWS, even though it's cheaper.
Only if your condition is that you want to do it in the next 3 years.
Given 15, I imagine quite a lot is possible.