If that's his mentality about stuff then like...why do anything ever in life if you wont be the best at it? Why have a hobby at all? (this all being sarcasm of course)
Smash should just be about having fun and enjoying the journey of self improvement. You'll learn patience, focus, depth of multitasking, and just to have fun doing something you enjoy with a community that does the same. I'm sure there are other qualities you'll attain that im forgetting about as well. but, I mean...why does HE play the game then, unless he thinks he'll win a major or something anytime soon.
Keep doin' what you're doin. Keep practicing and get better and work on what you need to work on to be better. Even if you dont do as well as you want you should be able to look back and see improvement regardless and that should make anything worth it. There will always be someone better than you. At that stage we just need to take it into small goals like "i want to win my first match in winners bracket" "i want to win two matches in winners bracket" "i want to take a game off one of the top players in my scene" "I want to make it to the round where they stream matches" "i want to win that match" etc etc. It's all in small steps anyway. Don't let him get you down with the saltiness