I'm also in this space - https://disco.cloud/ - similarly to you, we offer an open source alternative to Heroku.

As you well know, there are a lot of players and options (which is great!), including DHH's Kamal, Flightcontrol, SST, and others. Some are k8s based - Porter and Northflank, yours. Others, not.

Two discussion points: one, I think it's completely fair for an indie hacker, or a small startup (Heroku's and our main customers - presumably yours too), to go with some ~Docker-based, git-push-compatible deployment solution and be completely content. We used to run servers with nginx and apache on them without k8s. Not that much has changed.

Two, I also think that some of the needs you describe could be considered outside of the scope of "infra": a database + replication, etc. from Crunchy Bridge, AWS RDS, Neon, etc. - of course.

But tableau? And I'm not sure that I get what you mean by 150k/year - how much replication are we talking about? :-)