Well yes there are differences.
on multi-joint exercises (presses, pulls, squats, etc.) if you have a dominating muscle group among those involved that muscle group can take over and receive a lot more stimulation than others. If you only use one exercise per muscle group, and in that one exercise you compensate with another muscle group you might not get the desired effect. However if the exercise indeed focuses on the muscle you want to stimulate it might not be a problem.
if you do more work of fewer exercises you become more efficient at that exercise. Which can boost performance without necessarily building more muscle (which can be interesting if all you want it to lift big weights on some key lifts).
There is the possibility of not getting maximum fiber stimulation by only using one exercise. This would apply only to large muscle group and might not make a significant difference.
Anecdotally I think that multiple exercise have been shown to work best for hypertrophy, if not everybody training for muscle mass would only do a small amount of exercises by now since we would have figured out that it is better… but we don’t see it. HOWEVER I think that most people tend to do too many exercises, leading to too much volume and less gains.
i think that a dominant muscle will not lead multiple exercises while lagging muscle groups might need more direct work. In other words a muscle that is one of your strength might grow optimally only from one big basic lift, while a weakness might need 1 or 2 direct exercises on top of the big one
For example, I’m quads dominant…my quads grow fine by just doing squats. But if I only do the big basics (squats and deadlifts) my hamstrings and glutes do not get developed optimally, I need isolation or more direct exercises for these muscles.