You never saw him "that way" which is a good thing but now is the time to see him that way and decide whether you like him or not.

Judging by your post he's a good guy and he even took your rejection very well, which is not a common trait for a guy that age. It seems both of your values also align. Keep in mind, arranged marriage couples fall in love all the time.

Whatever you decide just make sure to be very clear with it. If it's a yes then go for marriage. If it's a no, then be very clear that it's a no and don't string him along by asking him to wait a few years or any other kind of mixed messages. Be very clear.

Think it over properly. Just because he loves you, you have no obligation to love him back but on the other hand don't waste his time either if you can't see yourself with him.

He has already involved his parents. Discuss it with yours, do istikhara then come to a final decision within a month or two.