This is not what I do.
I join with any group size within 1-5, on average 3 players.
1 of them is sometimes strong, most of them are dead average and it makes no difference if they are in my group or I would have players of similar skill in my team randomly, I keep them around because we enjoy each others company, not because I need their performance on the battlefield to carry the team.
I have maybe a tiny player quality advantage because of my groups and a moderate advantage because of my calls, it depends on how well the randoms listen. I no where nearly take full advantage of the potiential of a 5 man group. I could invite much stronger players.
Now compare that to a sync premade like Larkus.
Strategy calls with guaranteed obedience by a critical mass of players (because premade members are more reliable). 15 or more players who consistently pump strong dps and hps, better communication with voice. Over 5 healers every time plus random healers.
Can random players beat that? Random players who usually have no leader or communication whatsoever, who maybe get 2-3 players who fight well and all others do either poor or mediocre damage. Then there are objectives, random players often don’t understand which objectives are important.
Can random players ever beat a sync premade? Not in a 100 years.
Can random players beat a random team with a small group and a shot caller like me? Absolutely. It is tougher than usual, but doable and not unfair. Many random teams manage to defeat me.
You try to equate these two things and make them appear just like each other but they are very different. One is a small advantage within what is allowed and the other is shamelessly bending the rules for a huge advantage that guarantees victory 100% and ruins the game for your opponents.
If you claim they are the same, then stop joining sync premades for a month and only do what I do. Lead random teams with maybe 1-2 friends. You don’t automatically win every time because your team has a higher player quality. You will lose fights and you will have to compensate with strategy calls, where you can never be sure that people actually follow. And if that’s not enough, you lose.
Try this experiment and see for yourself that one is not at all like the other.
5 strong players plus calls plus discord is the maximum advantage that can still be considered fair, everything beyond that is just overkill and unfair. These groups can still be beaten, maybe not by everyone, but its not impossible for a random team.