People want to socially interact on a platform with the intention of letting you socially interact. I understand Mastodon intends to do the same thing as.BlueSky so the question is why is BlueSky more.popular.
As someone who uses both. Mastodon's UI and signup process is not as straight toward at least that is my personal reason why.
Your grammar and sanity are better for it. Actually, most cases I'm which a double that is used you can probably get away with a single that.