"Fairness" in matchmaking

Considering that players are expected to practice in unranked game modes, then from what I understand, unranked game modes just throw ALL ranks into one soup, is there even any attempt to induce a sense of fairness in matchmaking? If the players' skill gaps are too high, how exactly are we supposed to practice and learn when our enemies are already way high up and just ace-ing noobs every single round?

If practicing in ranked doesn't make sense and all sorts of reporting and verbal abuse will be thrown to players because we are trying to find enemies of more similar level to actually have a fighting chance, are we supposed to just practice in range or basic training? How can we actually prepare for ranked if we are already defeated in terms of skill gap because nobody controls unranked matchmaking?