The grass ain't always greener. When Dirk was on the Mavs, they were a good team for years, but still on a treadmill. Finally broke through and made the Finals in '06, but lost. Didn't get back for another 5 years and never sniffed the Finals again. Sometimes it be like that and it's ok. You're not gonna be a contender EVERY year
The Bucks tried when they paired Giannis with Dame, but injuries prevented them from reaching their potential. Ironically, it was mostly Giannis who was hurt.