There's a lot of problems that aren't being solved properly. For example, we've tried to integrate chat into our app recently and it was an absolute pain to the point we had to rewrite half the code because of the crazy latency on the servers, and hacking in some missing features.

Something like Framework7 is doing a good job of taking on Bootstrap or Ionic, but there's plenty of room there for improvement.

There's plenty of unicorns who could be doing a much better job - CRM, recipes, dating sites. I'd love to use a CRM but most of them are too complex, and you don't want to trust anything using vtiger with your critical business data.