Saban is the GOAT, undeniably so. that's without question. Even the GOAT is human, and can make mistakes.
Back to the Hurts situation - the OC, the WRs and most of the team were calling for change. Saban held fast and I am sure he had his reasons. maybe he thought Tua would make to many mistakes (2nd and 26 was 26 for a reason, remember), maybe he was overly loyal to a player. Whatever the reasons were, that doesn't mean he was right 100% of the time.
Take the situation with Dalcourt over the last 3 seasons. He was the weak link in the OL for almost an entire season in 21, with a frustrating level of play. When he got hurt, SM came in and the OL was instantly better across the board. 22 rolls around, and despite the improvement with SM playing the last few games of 21, DD is starting again, with the same results for several games. SM finally replaces him with the same result, the OL got way better, almost instantly. At that point at the end of 22, DD was a 5th year guy, but we invite him back for a 6th COVID year in 23, but now moves over and he starts at OG. It does NOT go well. He is eventually replaced by Roberts, and again, the OL play improves immediately. No break in period really, no 'dang that guy looks good and once he gets experience will be great', nothing like that - just instantly better. I'm sure there are reason DD was given the extra oppty to start in 22 and 23, but whatever those reasons were, they don't appear to be correct.
Again, Saban is the GOAT, and would be right in decision on what players to play way, way, way more often than he was wrong, but clearly not perfect.