In the NES and Super NES heyday I played a few games over and over and over again because I didn't have much money (that's a function of being a kid with no job) and games were expensive. So, I got comparatively few games, but what games I had I played a lot.
As a result, I played through a fair amount of games enough times that I got to be what I considered reasonably good at several of them (at least until speedrunning became a thing and I found a few videos on YouTube that changed that notion). At one time I had the Secret of Mana overworld map memorized, I could finish Battletoads in Battlemaniacs pretty reliably, and I could finish Road Runner's Death Valley Rally most of the time. I only got those skills through lots of practice, and, since I haven't played those games regularly in a while, those skills have waned some.
Since then, my disposable income has gone up, the number and amount of games has gone way up, and the time I have to dedicate to games has gone down. That's a recipe for cultivating a backlog (or, more accurately, preparing activities for my retirement). And to have any chance of playing through them in a reasonable amount of time, I've had to give up any notion of 'being the best'. Not that I really ever had that anyway. I play video games because I like playing video games. I don't play video games because I want to be the best at them, or even some of them, or even one of them.
High score tables don't drive me. Gamerscore doesn't drive me. Achievements don't drive me. World records don't drive me. Competition against other people doesn't drive me. Literally the only thing that drives me when playing video games is to have fun, unless I'm playing something like Super Mario Kart, then the thing that drives me is the go kart.
You might think then, that I'm some kind of casual nothing who only plays stuff like Tetris and Peggle and Dr. Mario, but that's not strictly true. I do like to play lots of games from a lot of genres. I like challenge, but I long ago gave up the need or the want to be the best Street Fighter player or the best Poker player or the best River Raid player and on and on and on. I'll still play them and I'll still go for a high score, and if I get one, then that's great, but if I don't, well, then that's OK, too. I'm not going to be entering any contests or submitting any demos to the SDA any time soon.
That also doesn't mean that I won't play head-to-head ever. I will still play pick-up-games of Team Fortress 2 online once in a while, or I'll play a few rounds of Street Fighter Whatever with some friends, and I'll lose more than I win some nights, and others it'll be the other way around.
And, just to stave off the inevitable email storm, if competition is what drives you, then that's fine. If having the highest gamerscore is something that's important to you, then go for it. I'm just saying that I've decided to have fun by not doing those things and having a wider variety of experiences that I take in on my own terms.
Which, in some way, means that I'm the best at playing video games the way I want to play them.