How do I get good?

[Zakyr]

Every time I play, I feel like I'm not going fast enough compared to others. Other times, I can't drift without bumping into walls or falling off, especially when a lot of turns are so strict that they punish you if you're not perfect. Even if I brake, I hurt my chances by not going fast enough. And using speed items is a massive gamble with all this in mind, it's too fast-paced.

How are people so good at this obnoxiously difficult game? Is there some trick I'm missing, but I don't see it when I practice. I feel like everything needed to get good is high level at minimum.

 

[c4rb0n0x]

It just takes a lot of practice, if you are having fun the skills will come naturally as you play. If you are talking about Gear 3, the description even says it's not as tightly balanced and I'm pretty sure the CPU cheats since I've seen it making insane 90 degree turns at 500% speed without even braking.
You should probably take the time to learn the tracks at lower gears or maybe try time attack, even if they are forced Gear 3 you can still focus on the track more since there is no CPU to bother you and it's less chaotic.
I've played quite a lot of racing games and I can tell you this one ranks near the top when it comes to difficulty, especially if you play on gear 3-4, and even more especially if you try to get the platinum medals.

 

[TinyGwen]

There are a few things you might be missing, but practice does make perfect!
To start i assume you've completed the tutorial and run a few GPs in singleplayer. The manual holds a lot of info the tutorial doesn't cover and has been extremely valuable for me in learning the game and its nuances. This includes sliptiding and wavedashing, which is likely what you're seeing others do to take hairpin turns at high speeds. (Sliptiding is covered in the drifting tutorial as of 2.4, but only in a small, optional section after the SPB chase, so you may have overlooked it)
When you're boosting (either from panels or sneakers), you can tap and quickly release drift while turning to begin a sliptide, which makes your turn radius extremely tight. You'll know you're sliptiding if you see a huge wave of dust kick up at the side of your kart.
If you continue to sliptide long enough, it'll "lock" and become a wavedash, which gives you bonus acceleration and speed. You can tell you're wavedashing when you see a vortex in the shape of a fan appear behind your kart, though note it has to reach a certain size before "locking". When it locks you can either continue to turn or start a drift to keep it going.
A lot can also depend on your weight and speed class. If you're playing a heavy/slow character, wavedashes last longer.
Eldog has a great video on the subject which goes into additional detail: Ring Racers 102 - Practical Sliptiding
There's a lot of videos on Eldog's channel that can help you understand advanced ring racers techniques too, like triangle dashing, good use of rings, and more.