As important as these things are, I imagine this type of thing will be either gamable or will push towards centralisation.
The cost for this type of thing should not be paid for by relays, it should be by the people. Zaps, donations, taxes, that sort of thing.
These things have costs, if they don't value the platforms (I say platform because I am talking about relays, not nostr as a whole) that they rely on, then they will ultimately fail to notice growing costs and will fail.
On one hand it sucks that something so critical is not guaranteed to work 100% of the time, on the other hand, if people care about that, they will contribute, either by funding or by alerting the alerters who seem to be slacking.