The EU mandate that all large messaging platforms be interoperable by mid 2023 ought to widen this gap too.

I wouldn't want to be part of the team having a deadline of March to develop and implement a way for every big messaging app to interoperate, with different user models, privacy concerns (e2e?), data storage models, data durability models, etc.

Yet if it launches late, you have that 10% of revenue fine hanging over you, which is huuuuuuge. And the EU probably won't listen to you when you say "we implemented this API but their API was incompatible with ours".