Elastic Cloud is far and away the best SaaS ElasticSearch offering.

It's in every way a better product than the hosted AWS ElasticSearch service, which I find to be practically unusable. More importantly, I don't know anywhere that uses AWS ElasticSearch where ElasticSearch is a core component of someone's platform.

The problem Elastic has is that their Cloud isn't remotely as good as self-hosting. Using their Cloud doesn't abstract away the domain knowledge needed to operate ElasticSearch at scale, so anyone who uses it and becomes competent will eventually self-host.

If they can get better at abstracting away the arcane knowledge needed to operate ES, AWS won't be a problem for them.