What show have you been watching the last 50 years? Most of the main cast of the franchise have been exceptional human beings, superior aliens, cyborgs and androids with the odd genetically enhanced hybrids or chosen of alien gods thrown in for good measre. The only people who are 'regular joes' are some people they meet and some of their subordinates, the vast majority of whom have been wet blankets by and large by comparison. Star Trek isn't 'average joes' in space and never has been. They are a group of people that are humanish, but are still able to save the galaxy every other week if needs be. Not even The Orville is that mundane, even if the crew can be pretty dumb at times to appeal to their audience and due to the limitations of Seth's abilty to write. The only scifi space show of note that even qualifies under that banner is maybe Red Dwarf, IMHO.
A lot of Trek characters were ordinary people. I'd argue everyone on TOS was other than Spock. On TNG, only Data and Worf were really extra special. On DS9 O'Brien was of course the everyman, but Kira, Jake, Quark, and many of the other characters were really just ordinary folks. VOY really only had The Doctor, Seven, and Kes as her "powers" started to develop. ENT was just a bunch of random, very ordinary folks.
One of the major appeals of the Trekverse - something that sets it apart - is that Starfleet is ultimately a meritocratic organization that anyone can join, if they work hard and study. I mean, it's obvious that all of the cast know more than we do. They're probably 2 standard deviations or more above average in terms of intelligence (since even boy genius Wesley had an issue getting in initially). But fundamentally they're mostly just people, not heroes with unique backstories. You can see this in how bad fanfic is written. People frequently fantasize about inserting themselves into the Trekverse. This stands in contrast to superhero stuff (or Star Wars) where the characters are literally of a different type than us - selected for greatness due to fate - and people tend to idolize the characters more than just relate to them.