Former employee, and you're wrong: pricing had nothing to do with it.

In 2017 we went under a feature freeze and no new features were allowed to be worked on. Anyone can look at the Heroku Changelog to verify this yourself (of course features that were in progress still rolled out over some of 2018). We had tons of attrition (without backfill) and even a layoff afterwards. Heroku is probably 1/3 of what it was at its peak around 2014.

SFDC gave up on us because we wanted to build a developer platform and they wanted us to build an enterprise platform. We sucked at enterprise features so they gave us the axe.