The first feature on benefits (and the only reason I've ever heard Datomic brought up and/or considered it myself for production workflows) is using that stuff in application workflows: https://docs.datomic.com/pro/time/filters.html#history

Could be you're saying it in fact doesn't work well performance-wise, that'd (surprise me but) certainly explain why it's not more popular -- but I think it's clear it wants you to use this as an application feature.