why do people use auto-concede?

just bought the bot, it seems doing fine so far in ranked game with auto-concede disabled.

is it becuz it is so easier to win faster at lower MMR/ranked?

And another question, i assume MMR and ranked are too separate things, so it maybe possible to keep up the rank with auto-concede disabled

and enabled for casual games to farm gold?

why do people use auto-concede?