In my opinion, the program should not create the link automatically when it sees a dot. For example:
Because sometimes we may need to use such a sentence - especially in foreign languages.
Maybe the program needs to recognize if you write http:// https:// or www.
It’s not just the “dot” that triggers this; it is when the renderer finds a “dot” followed by what it recognises as a top-level domain (TLD).
Apparently the Markdown renderer Joplin uses does not do this by default but it is switched on in Joplin.
This was discussed recently in this thread.