What you get for your $4,176 per year is the requirement that you pay $3000 out of pocket before qualifying for a 50% copay on most services. The well care visits, checkups and so forth, have no copays, but you're still out of pocket for the first $3,000.
Of course there are subsidies for the bottom quintile. But who will buy this without those subsidies? Participating DOES get you in network pricing (h/t Richard Mayhew for the reminder) which is a big deal as a practical matter. Sorta like Mafia shakedowns. $4200 for the right to pay $3000 out of pocket in network is a little steep.