I have a hard time with RPG's and Fighting games, even with Smash, and I wouldn't say I'm overall good with shooters, but for me I am better at shooters than RPG's and Fighting games. And even tho I am bad in Fighting games, I still would like to play Smash, or like to try Street Fighter, King of Fighters, etc.
With Smash, I barely go online because I suck. Every time, I play against people who always beat me, and I feel so ashamed of that. I feel like they laugh at me for being so bad. I usually play offline against the CPU, and that's just fine with me. I do hope Smash returns a big adventure mode, like Subspace Emmisary. I like Smash for the big crossovers, and even with only that in mind, I really want CJ from San Andreas.
But even with some Shooters, I feel the hatred on me aswell, like I played CoD on my PC and I randomly decided for once to turn on the voice chat, and people were really annoying since they insulted me of how I play. While if I turn off the VC, I feel more relaxed and focused on what I do in a match. In Splatoon, it's the same, altho I admit I can be annoying against some of my teammates at times, but I keep that to myself. But even I can suck hard at Splatoon at times, that I blame myself. It was very hard for me to get used to the Gold Dynamo Roller, but I did not give up on trying to master it, and I follow some twitter accounts of people who, like me, are dedicated on that weapon, and where I am jealous of how much better they are then me.
But in the end, even if I am bad at a game or genre, if doesn't really matter to me. I mostly play games at a relaxed paced time, and I really am not into competitive play, because all that stress for winning a game or tourney gets me really mad, and sucks out the joy of the game to me. I play video games because they are fun and give relaxation, not because I need to prove myself or others. Especially after a hard day's of work, I play games for that relaxation.
I tend to play some singleplayer games, but I do that on an even more slower pace, just to follow through the story at an more enjoyable pace. Years ago, my brother advised me to play Red Dead Redemption II very slowly, and I did. I finished the story through a whole year, and I am so glad that I did, since every little piece was still big to me, and I could emotionally feel how characters were written. Since november I have Red Dead Redemption on Switch, and whaddaya know, I still haven't finished the story, while I am going to.
In my opinion, OP, you should not worry about being bad at a game, but be glad that you enjoy it nevertheless.