A side question: Do you need to get .net/.org/.[other TLDs] when you have the .com one? e.g. google.net redirects to google.com, but google.org is for a diffe

A side question: Do you need to get .net/.org/.[other TLDs] when you have the .com one? e.g. google.net redirects to google.com, but google.org is for a different purpose.