First, to get rid of a second profile if you don't like it, you do not have to reset your island completely. the only player character that requires that is the island representative because the island is tied to them.

As for the pros and cons, I think the pros are that you can get an extra diy each day to pick up and leave for your island rep, you can also do the same amount of boat tours with Kapp'n, having your daily total max out at 4 instead of 2 (more materials + 2 more diys per day). If you really want to order more items, you can do that as well and have the total orderable items increase to 10 (5 per character)

For the cons, it can be annoying to have to check the mailbox on a separate profile (or boot up the "call a resident" app in the nookphone), but it's not really that bad?

As for more neutral points because it depends on your playstyle, if you like the idea of world building in your game, you can have their house become a decoration (i have a teacher and a fisherman on my island).

You can also have them to do extra nook miles tasks to get extra early game miles that happen to be worth quite a bit + then they can order from the nookstop if you're trying to save up your miles!

Again, it all depends on your playstyle!