(similar boat, use Heroku and some GCP in production for work) -- Heroku is great. But it is a bit limited and very expensive. It feels w/ modern cloud platforms you get something comparable with a little more flexibility for only a little more technical burden, _iff_ you have the chops. GCP / AWS are starting to encroach a bit w/ offerings like Cloud Run, I feel like they are one quality PM away from making a Heroku for Google type product that is a bit more powerful and a bit cheaper than Heroku.

Conversely, I also feel like Heroku could round out their offering just a bit more (ex: built in robust monitoring and alerting, better deploy notifications and healthchecks, a simple custom metrics system) and really lock in that "premium basic" tier that would be perfect for most small to medium businesses.