Their current database is still dramatically slower than log files. Waiting for journalctl to produce logs is consistently the slowest part of me working with my logs.

It's just a silly use of a database. I could probably count on my fingers the number of times I wanted non-sequential log records, and that's the only time I can see a database beating log files. Even if I want non-sequential records, Linux has a plethora of tools to manipulate and query plain text that everyone already knows. I would much rather use grep or awk or another tool I know than learn whatever arcane query syntax journalctl supports.