Why is it so much faster connection when I use obfs4 bridge connections?
In theory, could I host my own obfs4 bridge on a VPS with good specs just for a fast speed? I’d be the only one on it right?
Yes.
Yes.
See also Configure (Private) (Obfuscated) Tor Bridges and search using the browser’s internal search function for the search term
private
for some further information.