So, I've noticed this being an issue in the past month or so, but I chose to ignore it. What I've noticed is that respawn timers are way too long. Past the 25 minute mark, your respawn time can be anywhere between 30 seconds to 45 seconds, which is enough for a team that is incredibly behind to win. It's ridiculously unfair. Not to mention that the towers themselves are very, very weak. Even a mage can just chunk away a tower without much effort.
You can be absolutely crushing the enemy team, but as soon as you lose one team fight, it's game over. It shouldn't be like that at all. It doesn't feel like anyone made a comeback. It just feels like knowing how to play the game doesn't matter anymore. If the enemy team doesn't really get any objectives but you lose one team fight at, say 30 minute, you can lose because the towers are so weak, and you won't respawn for another 30 seconds.