>>538321224
>>538321363
>>538321462
>>538321756
>>538322098
Actually we have recent data on this.

According to the results of a Professional Survey with a share of 30 000 japanese participants aged between 15 and 69 (data provided by GEM Partners).
https://xtrend.nikkei.com/atcl/contents/18/01178/00010/
The results indicate that:

Nikke
>Average Age: 27
>Male/Female ratio: 70%/30%

Blue Archive
>Average Age: 25
>Male/Female ratio: 90%/10%

Honkai Star Rail
>Average Age: 25
>Male/Female ratio: 61%/39%

Genshin
>Average Age: 26
>Male/Female ratio: 58%/42%

Zenless Zone Zero
>Average Age: 26
>Male/Female ratio: 76%/24%

Monster Strike
>Average Age: 28
>Male/Female ratio: 88%/12%

Disney Twisted Wonderland
>Average Age: 28
>Male/Female ratio: 4%/96%

Idolmaster
>Average Age: 29
>Male/Female ratio: 65%/35%

BanG Dream!
>Average Age: 30
>Male/Female ratio: 74%/26%

LADS
>Average Age: 30
>Male/Female ratio: 2%/98%

Love Live
>Average Age: 33
>Male/Female ratio: 79%/21%

FGO
>Average Age: 33
>Male/Female ratio: 60%/40%

Umamusume
>Average Age: 34
>Male/Female ratio: 84%/16%