Sure, there are those people, but that’s not the point here. Lemmy doesn’t enforce some arbitrary short length to its posts in an attempt to force the users to engage more with the platform instead of the actual content. The same cannot be said of tiktok or twitter, for example.
You might want to give some sources for that claim.
This article from Time summarizes quite well my view of the issues related to attention span. This is certainly not limited to the likes of tiktok or twitter, but I think those can be considered as representing two of the worst platform formats for meaningful content.