Doc sucks, but Budenholtzer had the best team in the NBA for 5 years and only even made the NBA finals once. At least the Bucks got one championship, but they really underperformed during Giannis and Middleton's career.
I am willing to give them a mulligan on the 2022 playoffs because Middleton was out, and getting to the conference finals in 2019 was respectable, but two early round exits to the Heat (2020 and 2023) are inexcusable, and now this year. The window for an NBA team to challenge for a title is short, and the Bucks' window has closed.
It is also worth pointing out that the Bucks got really lucky that they even had this window. Giannis was the 15th pick in the 2013 draft. Giannis was playing in the equivalent of the Greek G league, and there have been different stories about whether anyone in the Bucks' front office had even seen him play prior to his getting drafted, or if they were going off a European scout's assessment. No one on any team had any idea Giannis would be remotely this good, because if anyone did, they could have easily traded up in the 2013 draft, which was probably the worst draft since the ABA/NBA merger. Other than the Hawks, there are also no contemporaneous reports from 2013 that any other team even wanted Giannis. Giannis is the equivalent of a unicorn riding another unicorn.
Middleton was a second round pick of the Pistons in 2012, played much of his rookie season on a G-League team, and was traded to the Bucks the next offseason as a throw in on a trade between two mediocre point guards. The Bucks sucked so badly in 2013-2014 that they had to play him, and even then it took him three seasons to really emerge.
Basically, the Bucks got really lucky on both players, and prior to the Bucks making the conference finals in 2019, they had not won a playoff series since 2001. This is not exactly a franchise that exudes greatness.