Bear in mind this is a beta product, it's being actively developed (e.g. signals like in solidjs are coming soon, which is a pretty major feature) and the API is probably going to change quite a bit in the following months.
The people that want to "speed up their site" are not the target audience at this point, it's developers who know what hydration and resumability are.
Very few web developers are "keeping up-to-date" that quickly. I've been aware of it for a while, but the vast majority of devs are not aware of tools until they hit mass adoption.
Bear in mind this is a beta product, it's being actively developed (e.g. signals like in solidjs are coming soon, which is a pretty major feature) and the API is probably going to change quite a bit in the following months.
The people that want to "speed up their site" are not the target audience at this point, it's developers who know what hydration and resumability are.