I think the average person in the pew is under the impression that confession is something old-fashioned that isn’t done much any more. I would guess that most haven’t been in many, many, many years and feel so lost and out of practice that even if the thought would cross their mind, that they would quickly put it out of their mind because they would be nervous and not have a clue where to start. Most just go “straight to God” with their sins and since it’s been working just fine like that for years, they see no reason to change.
I think there needs to be some basic catechesis on the sacrament and related practical aspects - probably during the homily. Starting off with why priests have the authority to bind and loose, what sins need to be confessed, the benefits of the sacrament, a how-to with a cheat sheet in the bulletin, a primer on how the lights work over the confessional, what to expect when you walk in the door (details on options like screen and face-to-face). All followed by a invitation - probably a repeated invitation - no RSVP needed.
The longer you don’t go, the easier it is to continue not to go. After all, we’re all basically good people, right? (except we’re not called to be good, we’re called to be holy)
Our parish has confession before daily Mass - that would be at 6:15 a.m. three days a week, so you know that the average Catholic in the pew is not going to be there at that hour. Noon on Wednesdays and from 3:00 to 3:30 on Saturdays. Our priest is an excellent confessor, but very rarely have I had to wait in a line.