The worst part of a relay race is if you have a teammate that's basically a dead weight. I used to swim competitively, and at each competition, there was always a relay race. 4 swimmers would need each need to swim one of the 4 main types, backstroke, breaststroke, butterfly, and freestyle (in that order). There was just one issue. Our backstroke swimmer really wasn't up to par which resulted in me always having to start my laps from last place. It's really not fun having to chase and make up for another's mistakes instead of lengthening a lead. Our relay team always performed relatively decently, but we could've been so much better.
Although I want to say that I didn't really mind it that much, it really takes the fun out of a sport if you constantly start with a disadvantage.
It probably also didn't help that I had basically no contact with that individual, although one of the other relay members was a friend of mine.
Luckily, that was the only event that depended on the performance of others or I might've ended up disliking swimming.
Although it may not seem like it, based on what I've written, I actually really like team sports having played both soccer and handball for many years.
I just don't like relays (unless all the members of the team are my friends 😂). It's basically the difference between playing to have fun and playing to win. A combination of both is obviously even better.