Besides the nostalgia factor, some of the new younger girls doesn't carry on the same charisma as them. However, they are above 30 now with Rio just turn 30 a few months ago.
Honestly, I'm not sure if they use their real birthdates so they might even be older. Mihiro been filming softcore v-cinema for quite a while before av. In American porn, teenage girls tape their real names on their driver license in the intros. I know you can still fake it, but we don't see that in av instead we get more staged warm interviews for their debuts. Some even share their childhood and school photos like Rio and Aino back in alice japan and max-a.
Most of them that are still active on Social media and the entertainment industry are either married, pass their prime, or got a stable job. They might have a few wealthy heirs or businessmen backing their luxurious lifestyle by being their mistresses since most Gravure idols and av actresses join av for fame and fortune. Besides, It's hard to get back out there without a degree and even if you manage to get a job using your porn and av money, they can find a excuse to fire you. It's kinda ironic situation.
Btw maria ozawa face look swollen or bloated these days and she tries to hide her acne scars using a lot of makeup. She also gotten quite a tan from the phillipine weather. Mihiro and the others from akiho generation are maintaining their youth and figure quite well. Too bad there's no news about yua aida. Next year there will be debuts from the year 2000 and I remember people talking about 1991 almost 9 years ago. That was around the same time the first muscat was form. Feeling old, but as the girls get younger the guys get older both in Av and western porn since they use the same experience actors.
above 30 (if they faked their age I think 5 years top) they still don't have menopause yet, they still can perform well, so still possible to comeback into AV
american and japanese have different culture, including in their porn we see different style, different rules
yes thats the similiar reason why I believe they have big possibility to comeback, like you said most of them don't have degree, and with their ex AV idol status more difficult to find good job out there; with current economy condition its also more difficult to open their own bussiness or get sugar daddy that can support them
yeah times goes on, its already 20 years past since the 90s