Because Katy Perry has no artistic integrity at this point.

Fergie?

I think people say that to undermine Katy's success.

The examples you mentioned don't match the level of childishness Katy portrays most of the time.

Fergie and Gwen do not cater to teens, do they ? Gwen and Fergie are very sexual and immature in a mature way.

Fergie is not childish she is cool. Katy is childish. there is a difference.....

Because 20s are the coolest ages, not beginning of 10s

Even before Prism, her peak, people already criticized her for it. Heck, even before Teenage Dream. But if she wants more and more hits, then I guess she should stick with the material she has. I still like her work anyways.

39 - 20 = 19
45 - 20 = 25


30 - 20 = 10

J-Lo and Gwen act/look young but aren't childish and don't make music that sounds like it's aimed at children unlike Katy

Well no one cares about Fergie and Gwen anymore. Jlo has other talents for credibility (dancing) so I guess she's excused. I mean Madonna still gets dragged for acting 50 years younger than she is as well

this tbh plus the overall jealousy.

Because her main demographic are grade schoolers.

Not Fergie when she looks 50

People want Katy to act her age because ever since she debuted she hasn't evolved musically a single bit, she's been serving the same sound again, again and over again. People would like her to try new things, that's what I think.

Maybe you should re-watch her Birthday video and see why people tell her to grow up. She is literally jumping around with 5 or 6 yr old kids in a pink barbie dress. NO pop gurl would ever do it except for Katy. Its just silly & so childish.

Go look at how she was dressed up at that Football even that she recently attended. I mean if a 30 yr old woman is going to dress like that, them of course she is going to be called "immature" or "childish".

Also most of her lyrics are a cringeworthy mess, full of cliches and whatnot...and that's not the case with Fergie, Gwen or J.Lo.

Infact the latter 3 have a very mature image & lyrics.

If you hear her albums, you'll see her music isn't some teeny bopper.

Also, what's so kiddy about "Unconditionally", "The One That Got Away", "Birthday", "ET", "Waking Up In Vegas", "I Kissed A Girl", "Thinking of You", and "Hot N Cold"?

The fact of the matter is, Katy is being stereotyped by her "Teenage Dream" era look because it had too much impact that they are still living through that era. This just proves how successful and memorable Teenage Dream was no matter how hard they try to shrug off its success.