I feel like nobody external really totally understands it. Heroku kept going fine for some years after the initial salesforce purchase in 2011 (heroku's real launch wasn't even until 2009, so arguably most of the "golden" years were post-salesforce... )

I would be very interested to see a balance sheet, like how much revenue and how much profit for heroku specifically, over time. But that's known to nobody outside of salesforce so far as I know. Neither is how their staffing may or may not have changed over time.

We have seen heroku kind of stagnating, and maybe having more technical problems, which they handle without the professional polish we had previously expected, and now get rid of free tier -- and there have been a few pieces kind of saying this, but what I'm interested in is... why? What's happened?

I have seen various people speculate, including that it may have been doing quite fine well in the black as an independent unit, but salesforce has always wanted it to be more "synergistic" with their other business than it has been, and just wasn't interested in investing in it. But maybe it hasn't been that profitable? not sure anyone publicly really knows?