He is still young, so recall can get better. Keep training and when his head is more mature he should get better at it
I live in a country where castration is only done if there is a problem. So most dogs are intact here without any problems.
If a dog has issues and castration is considered, we usually do a trial with chemical castration first to see how it affects behaviour. This is a good idea because it is not permanent.
Some insecure dogs can get more behavioural problems with less testosterone, so we only consider castration in confident dogs. Unless there is a medical reason.
He is not too old for the surgery. But he is young enough that all this stressing and recall problems could get better when he matures.
I'm not against or for castration. It's just good to know there are options
If you feel he does not get enough time off lead you can still tire him out with working his brain more. Nosework, obedience, party tricks, balancing on things in nature etc. Fun activities to be had with a long line
Oh, and you are not selfish either way. There is no perfect answer. This is a case by case type of decision. So when your goal is to do what's best for your dog, you are doing it right by default in this type of choice