I can relate to this, my overall win rate is about 40% on For Glory, partly because I try a lot of random characters I don't know how to use and I consider myself a scrub that is above average skill level of most Super Smash Bros. for Wii U players but that's not good enough. I also occasionally get compliments about how much better I have gotten when I replay skilled players in the Discords that I'm in.
Most of the time I compete in tournaments (mostly online but occasionally offline tourneys as well) I usually get eliminated instantly and it can be discouraging to want to continue playing a game in which other people are more skilled then you and it seems you're not going to catch up.
Smash can get frustrating and a lot of times a lot of people feel like quitting, what I end finding is people that care about Smash 4 never really "quit", they stick around to at least just chat with others. There's very few people I know that actually have quit because they want to move on with their life to do other things entirely and even then at least one of them still come back to check in and see how everyone is doing.
You have to keep in mind that even the best players in the world feel this way too.
What I do about this
What I personally do is I take breaks when I have consistently lost a lot of matches within extended periods of time. I stop playing Smash for a while. The reason I do this is because I find playing Smash to be like any other creative medium, such as drawing, developing games, using Photoshop, or anything that can be tedious or time consuming. Sometimes I feel the need to take a step back, do something else so that when I get back to it I look at Smash with a new pair of eyes. If I were to continue playing after long losing streaks I feel that I would likely continue losing because I would keep using the same moves and similar habits that I have been using in previous matches.
The reason I never officially quit playing Smash Bros. is for two reasons. The first reason is I'm a social player, I like playing Smash Bros. to talk to others as opposed to being the best or exploring the game at the greatest depth possible because in my opinion those two things can be stressful, so with social player I feel I don't have to worry about being the most knowledgeable or being the very best and therefore I always have a reason to stick around. The second reason is because I try or I try to try my very best in every match that I play, especially when playing other players I respect because it feels great to know that I gave skilled players that I recognize a challenge. Every once in a while I feel like I will go Super Saiyan, be in the zone and play much better than usual and even if I don't win it feels great to feel these small burst of energy that help me focus and help me make smarter choices or pull off riskier options with ease.
Knowledge is useless
Also I believe in one core thing that is really true universally across anything you're trying to get good at. Practice, practice, practice. In my opinion all the YouTube videos, all the informative posts, the frame data, maybe even coaching and anything thing that can give you an edge in knowledge is useless if you don't apply it or don't know how to use it. Personally for me (I'm not saying this will apply to you) I feel like being more knowledgeable in Smash isn't going to help me improve, I don't 100% disregard it but it's not at the top of my priorities when trying to get better at Smash. In my opinion it's much better to take things out in the battlefield as opposed to trying to gain all the knowledge about Smash in the world, of course being knowledgeable and knowing how to apply the said knowledge it is the sweet spot but not everyone can use experience and knowledge and merge them for better game play.
