No shade here at all, but I always figured this was intentional. One legitimate way to get people to pay for OSS is to make it a real nightmare to self-host.
edit: Just wanted to add, I say this as a happy Sentry paying user for more than a decade now.
It's not intentional. We actually held back more complicated features for years to make it easy to self-host (e.g. only used Postgres and Redis as data stores for a long time).
The complication really just comes from the new capabilities we've added, and the dependencies that come with that. I suppose also our sophistication in hosting the platform has evolved (as the scale has increased), and so the tooling we use to manage it has become more complicated.
Kudos! And I get it, it's hard to do really cool and powerful things when large amounts of data are involved without involving better (and possibly more complicated) data stores.
edit: Just wanted to add, I say this as a happy Sentry paying user for more than a decade now.