Well, consequently a huge portion of computing has migrated to the cloud since 2014. But we were running ES in prod on self hosted instances back in 2012. It was very well known then. With or without Amazon's ES service it would have thrived. The reality is, ES solves a core problem for application developers. If you have that problem and you need indexed search capability, you go find it, because building it yourself is difficult and time consuming to do. Agreed that permissive licensing was a big part of its adoption, but people would just be putting it on EC2 themselves without Amazon's managed offering (and many probably still are).
It's not about whether it would have thrived without AWS, it's about 1) Would it have thrived at all under a more restrictive license that could have reduced adoption; 2) During it's old license, did it thrive more than it would have without AWS adoption.
Counterfactuals like this are difficult to answer. However, more permissively licensed software does seem to reach widespread adoption more easily. Elastic's download rates seem to have approached hockey stick growth trend around the time of AWS adoption, and Elastic's revenue significantly increased afterwards as well. It might have been on track for that anyway, but 5 years of linear growth did turn sharply upwards around AWS.
It seems like Elastic as a company has a decent probability of faster growth and more revenue due to market penetration and name recognition assisted by AWS usage.
Had Elastic been restrictive.from the start, it's entirely possible that the industry would have focussed on and driven improvements in something like solr instead. As you said, elastic solved problems people had, it's not unreasonable to think they would have solved them some other way without elastic.
I put that into the unknowable column. If history were different and AWS hadn't used them, perhaps the critical mass wouldn't have happened. Or perhaps it would have.
