I think the biggest thing to keep in mind is that leagues that don't have any issues rarely make changes. The reason MLB is making so many changes is fairly simple; it needs to attract more/younger fans. The 2020 playoff structure is clearly a revenue grab to compensate for Covid related losses, but in the long run, they need more national TV exposure. They need more fanbases to be engaged during a longer season. They (badly) need attendance to rebound after fans are allowed back in. Expanded playoffs is going to help with some, if not all, of that. It's not about the "purity of the game" anymore. It's about adapting to the current climate.
Right now, had the league not implemented the expanded playoffs, the following teams would be out of playoff spots in the AL: Yankees, Jays, Astros. You have the biggest franchise in the entire sport, the biggest villain in the sport, and the Jays (ok, this just benefits us fans, but still). Who the hell wants to see the playoffs with the Rays, 3 Central teams, and the A's battling it out? In hindsight, expanded playoffs saved the AL playoffs this season, assuming the standings remain as they are.
We'll all get used to this eventually. Just like we did the initial Wild Card implementation, then the 2nd WC implementation.