identifying the best team. They're not a reward for a great regular season. They're tournaments. The regular season is how you qualify for the tournament. There's no way for a team to strategize to be just good enough to win the wild card but not good enough to win their division or have the best record, so the "disincentive" people talk about isn't a real thing.
In any tournament, the "best" team doesn't always win. The Dodgers aren't losing because they had a few days off, they're losing because they don't have enough healthy good pitchers to beat good teams. They went 5-8 against the Padres in the regular season.
The expanded playoffs are doing what they're supposed to do - make the end of the regular season and the playoffs more interesting and more exciting for more fans.