Disagree. I feel like this happens all the time where a "rising" team suddenly has a rash of injuries, their fan base just says "wait til we get everyone back!" and it just...never really happens. 1 or 2 guys come back, a couple are never the same again and they middle around in mediocrity for a while and disappear.
The focal point of their offense is now a 29-year-old RB coming off IR with 2,000 career touches. Purdy has always been completely unimpressive to me.
They haven't looked good this year. At all. Before anyone got hurt. They haven't played a single strong game. And to your point, they really aren't even a young team, either. Deebo is 29 next month. Statistically they are the 7th oldest team in the league. They're closer to a blow-up than a comeback. I wouldn't be totally shocked if they eek back into the playoffs, but this version of them lost two Super Bowls. They're coming down off that peak.