I'd estimate that 2/3 of my games go something like this:

Someone is late to the match, buys items and leaves base at 0:55, we've already been pushed off our Blue buff because the enemy team did a 5 man invade, so they show up late and try to force something, get chunked out because they ignored everyone's danger pings, and get to lane late after they're forced to base.

Their enemy laner gets a surprise level 2 all-in because they missed a couple EXP on the first wave, and they die.

Coming out of lane phase they are 0/1 and down 40 cs, and start flaming everyone else on the team for how bad they are. They decide to sit in the fountain the rest of the game telling everyone exactly how bad they are and how they always get shit teams and that's why this game is so terrible.

Someone else on the team is memeing and trying to keep everyone's mood up, jungler is on autopilot just clearing camps and getting killed because both side lane outer turrets are down, and spend their death timer flaming back and forth with the first player, and then the support decides he's had enough of being blamed and disconnects from the game. Then reconnects 5 mins later and says "sorry had to restart my router"

The first player continues to flame everyone while sitting in fountain, sells all their items and buys a single tear, and watches as we NEARLY win a 4v5, if only we had a bit more damage.

Game ends, someone on the enemy team says "GGEZ"

Everyone spams "report so-and-so" they say "lol for what???" someone tells someone else to "stay Iron kid," top laner says "gg fun lane" enemy top says "yeah sorry about so-and-so" mid says "hey just a suggestion but never play that champion again, no flame" and then I close the game and go play something else for the rest of the night.