The most popular member should always debut first.

They set the bar high so when less popular ones debut, fandom try to achieve the similar level of success.

Quote from OP

They set the bar high so when less popular ones debut, fandom try to achieve the similar level of success.

And the risk is, if the fandom does not achieve that similar level, it reflects horribly on the 'already less popular ones'

Are you contrasting the debuts of Nayeon and Jhope?

Then that is not enough data to assume either way.

I mean Jennie debuted first with BP, still was succesful as hell then Rosé and Lisa were also succesful as hell, so...

I mean, yeah it makes sense. There's a higher demand for popular members, and companies should always follow wherever there's more money. It doesn't make sense for your money maker to be sitting in the basement while other less popular members are debuting solo etc.

Quote from Dried Beets & Lemon Turkey (233)

I mean, yeah it makes sense. There's a higher demand for popular members, and companies should always follow wherever there's more money. It doesn't make sense for your money maker to be sitting in the basement while other less popular members are debuting solo etc.

That's why we rarely see this happening. Companies only invest in popular members but if, by chance others end up getting a solo career company doesn't put the same energy.

Quote from Poached Light Beer Lamb (409)

I mean Jennie debuted first with BP, still was succesful as hell then Rosé and Lisa were also succesful as hell, so...

Jennie's solo definitely did some work in raising rosé solo expectations and hype among gp. YG made the right decision.