Information about the matchmaking algorithm

Good morning everyone, I wanted to ask a specific question to understand certain choices in the game. I wanted to know the logic behind the matchmaking algorithm. As far as I'm concerned, such an algorithm should seek optimal team balance, but its choices often leave me very perplexed, and so I don't know what to think. Thanks in advance to anyone who can answer me.

PS: I opened a similar thread in the Italian forum, perhaps criticizing certain choices made by the algorithm, and I never received a response, so I'm opening a thread here too to understand what to expect from each matchmaking process.