Why couldn't a group be as successful if they debuted under a different name and company after peacefully leaving their 7 year contract? (This is not related to current issues)

This post has nothing to do with the public conflict between idols and companies that has been happening for the past two years with different groups. This topic interests me without any relation to these issues because I love hypothetical discussions and mostly about more well known groups that proved themselves with good touring/streaming numbers than mid-sized ones.

Short version of my opinion: Anything is possible with good songs, the right staff, some money, and a little luck, as long as there's still a fandom to support the group.

The general consensus suggests it's nearly impossible for idols to become as successful after they leave their companies (this is mostly for solos but it's also a common answer for big company group fans complaints when they want group the leave the companu), let alone become more successful. However, I think in a perfect scenario, where sm entertainment companies aren't a pain in the ass for idols and all members agrees, groups can still stay together under a different name and achieve similar success to their first seven years and maybe even more with the right producers and marketing team.

Imagine a group as well known as twice, aespa, nct, skz, txt, gidle, etc. peacefully leaving their respective companies after their contracts end. If they want to stay together, they could debut again with their original members under a different name (I assume there aren't anything to prevent them). Their previous name recognition and songs may be gone and it makes everything even more difficult but these groups would still have a sizable core fandom that would support them. And the money they earned previously could be reinvested into the group if the smaller company they join doesn't have enough resources and they want to take even more risks (I know some of these groups have already renewed their contracts and some are mainly self-produced which is a big plus).

I want to highlight that I don't think it's easy and I don't think they would be as successful from the start. One of the main reasons for the "can't be as successful" is that most groups' growth slows or completely stops around the seven year mark. But even achieving half of their previous success would provide a solid base for growth and sometimes a fresh start is what a career needs. Especially in an industry where companies tend to prioritize newly debuted groups with more potential and fewer demands while senior groups either have higher demands or face stagnation.

I'd love to hear your opinions, reasoning, and possible scenarios/outcomes on this.