While I think there is a benefit to difficult divisions with more skilled competition, I think there is a balance to be struck.
Saying that the kronge realm team history being not straight wins is a bit disingenuous if you take into account that they were facing other teams with other "sandbaggers', for example, in S10 where they got 3rd, the other 2 teams who were above them were also made up of multiple players with invite/adv winning experience on their mains.
The pipeline back in the day used to be get 5th or 4th in adv(ESEA-IM), move up to invite because everyone above you in adv already had invite experience, once you hit the wall in invite and want to take it easier, come back down to adv. Adv was never about actually competing at a high level, it was what invite teams did when they stopped wanting to face the top 4 wall in invite but still wanted to feel some competition. (This is not always the case, I remember Omni-5 w/ fyg hayes cin putting good numbers against the top adv teams before they moved up to invite, but this was a rarity.)
Personally idc where the line is. Ultimately, there are always things you can improve on. But I don't think it's that far-fetched to want the invite caliber teams in invite. and use Adv to develop players/new rosters.
Instead of these top 3 adv teams being in adv, they could literally just play low invite and create more competition in low invite. Instead of 3rd place adv being the bar that people need to reach, why isn't winning adv the prerequisite to facing the teams of low invite? I'd argue that most of those seasons Konge Realm won/placed, the top 3 teams in adv were better than the bottom 2 invite teams, and many of those seasons, the invite division had room to be bigger. (id also imagine low invite not being such a slog if there were 4-5 low invite teams as opposed to 1 or 2)
The rule where they made each team only have 3 restricted players made more sense from an ideological standpoint because it meant that developing rosters could form where 3 invite players developed 3 other players and tried to win adv, but more often than not what you see is admins approve those teams with the 3 new players and 2 of them get cut and rosters rotated onto their mains by the time the playoffs starts. (see Fjord Gaming/Quake these last few seasons). Most of the time, I don't see those other players starting new rosters with budding potential either. Usually, what we tend to see is those newer players who made it to the playoffs stay with that same core who may or may not play (and if they do only want to play adv), and the other players who didn't make it don't play the following seasons either.
Ultimately, incentivizing people to stay playing adv is what rgl is trying to avoid. While I don't agree with all of their restriction changes, I do think it's a good idea to not let teams just take their 6 down from invite to adv or get 3rd and wait 2 seasons and not play invite just to play adv again. and rinse repeat for the next 3 years because theyd rather continue playing their current division than try and make a jump into new territory.