A single person can't do all 3 of those things, that makes perfect sense.
A single person could, however, hire people to take care of some of those issues. Is that correct or just my being naive?
Yes, but you need money to hire those people. Where will you get the money? You won't get any investor money until you get a team, you won't get a team until you get money. Those other people are going to have to be co-founders.