Nobody is forcing you to watch all 18 innings of a random regular season game. You could, say, turn the game off and go to bed and watch the highlights the next day!
They didn’t happen often but they were fun. I remember a decade ago watching John Baker come in to pitch because the Cubs ran out of pitchers, throwing a scoreless inning, then scoring the winning run in the bottom half. Maybe they’re more fun for me because even a late game doesn’t actually go that late on the West Coast (I went to bed by midnight last night)
I would also argue the stress on a pitching staff is likely greater in the playoffs because you can’t just call up a couple relievers to fill innings the next day. Like what happens if either starter gets rocked tonight and only goes 3 innings?