Which non HBO show had a great premise but was poorly executed? Could HBO have done it better?

I loved The Leftovers and the angles they took on belief and cults. After I watched the Path on Hulu which is more of a look at a single movement/cult. I give the premise a 10/10 but the production about a 3-4/10. Everything from casting to writing was lackluster to outright bad. By the third season the executive producers were also the lead actors which is almost always a terrible sign. I think HBO could’ve made it a stellar series. Higher budgets, great casting agents, and letting the creators do their thing would’ve really improved it overall. Any thoughts on this or shows you thought were okay or bad that might have done better on HBO?