Transactions aren't what currently limit scaling (network growth). It's onboarding (account creation) that is the bottleneck.

SplinterLands experienced that limit in 2021. Thus Hive just couldn't be an instant alternative if there was for instance an exodus out of Twitter looking for a new home. Hive can't facilitate the user numbers established platforms manage.

FYI: SplinterLands recently changed their transaction confirmation from 3 second to 45 seconds because they often fill blocks and need to move transactions ahead. So even by your own example, Hive is at its limits and that's JUST from SL data.

There's no way Hive could handle 3, 5, 10 projects like SL. Block size can be increased but core devs don't want to do that. In fact, core devs deliberately made custom_json more expensive because they would prefer to push SplinterLands out as core devs and SL devs don't get along.

Hive is a strange beast. Claims to be the greatest Blockchain, but deliberate doesn't want to be very user/business friendly.