While this maybe true (re. Hamza) it’s very easy to say in hindsight. Everyone I know thought it was the right decision at the time, myself included.
Puel obviously had a lot of faults which were unforgivable but he has to take some credit for the squad age change etc. It’s not just a case of playing the younger lads but more that there wasn’t a noticeable drop in results (let’s see how Chelsea do this season if they persist with youngsters for example).