MySQL needs the cache more often though with a limit of one index per query. Postgres seems like it more often can combine a few indexes and turn what scans 100k rows in MySQL into bitmasking two indexes and pulling 10 rows.
Seems sensible, each has features to support the base design.
True point (disclaimer: don't know how mysql has evolved in the past 5 years).
Fits with my general feeling of "if you want to optimize for a super specific use case, sometimes mysql can provide some cool tricks for that use case that can be amazing" but if you want a more general solution if you need more flexibility or don't have the knowledge or don't know your future needs, postgres shines.
Seems sensible, each has features to support the base design.