I feel like finding out a house you bought doesn't actually have internet after the fact makes it worthless in the modern world and should be a valid reason to reverse the purchase.
The closest I can think of off the top of my head is requiring a working (and testable) fiber connection before signing, and refuse to close if there isn't one. I have no idea how that would impact trying to buy a home today.
Here in the UK at least companies are not allowed to lie about which houses can and cant get service, and there is a regulatory body (ofcom) that regulates this and other telecommunications service aspects.