Imagine thinking that shitting on Dubas somehow excuses Sullivan.
Very few Penguins fans would argue against the thought that Dubas has done a terrible job as the Penguins GM. That doesn't change that Sullivan has been an awful coach for the Penguins for pretty much 5 years now. Any normal team would have fired him sometime in the 2020-2022 timeframe, yet it's about to be 2025 and we're still watching him.
Bylsma won a cup in 2009 and had playoff failure after failure after that. Despite that, he won a playoff series in 2010, 2 playoff series in 2013 and a playoff series in 2014 before he was fired after 2014. Sullivan hasn't won a playoff series since 2018 and they're now about to be 3 years missing the playoffs, yet there is literally zero question about Sullivan's job security.
Or if you want another example, Quenneville won 3 cups for the Hawks from 2010-2015. They then lost in the 1st round in 2016 and 2017, missed the playoffs in 2018 and was fired early in 2018-2019. Quenneville had more success yet still didn't last 5 playoff losses and 3 missed playoffs after his last cup.