Ok, I feel like people are sort of out of perspective on this conversation.
Teenage Dream was one of the most successful albums of all time, looking at relative album sales and the singles it spawned. It's equal to Michael Jackson's Thriller regarding how the singles succeeded, and in an era where albums sell less and less, it sold more than 6 million copies worldwide. She followed it up with Prism, an album that allowed her to grow and mature while still spawning two more billboard #1s. It sold almost as much worldwide and was even more successful in some regions saleswise.
Then came Witness. Maybe her most coherent album, where the sound was clearly inspired by early 90s music and she wanted to write a more sophisticated album. The lead single got to #4 and the album topped the Billboard charts. Obviously, that is far from how some people compare her to how Bionic flopped. Witness was creatively a very interesting era. Her music videos were inspiring, and songs such as the title track, Swish Swish, Chained To The Rhythm and Pendulum are among the best and most creative she's made. If any mistakes was made, it was releasing Bon-Apetit. Instead she should have opted for Witness and Hey, Hey, Hey as third and fourth singles and closed the era with Swish Swish (along with a better music video).
Katy Perry has always been an artist more inspired by Alanis Morissette than Madonna, MJ, Janet, Mariah or any of the alike. She's been more in the pop-rock adult top 40 folder of music and continues to be. 10 years ago, that kind of music had it easy to reach the top of the charts - look at P!nk and Kelly Clarkson also having several #1s. As someone wrote, the music that tops the charts is more hip-hop, rnb and Ariana (basically, music with less bold melodies and instruments).
So yeah, Katy is unlikely to get a number 1 single this era. Yeah, she is not as dominant as she was 10 years ago. But neither is P!nk or Kelly Clarkson even though continuing to achieve great successes with their music. Her album might still top the Billboard 200 and be a great success. An album not reaching the world domination that Teenage Dream and Prism achieved does not mean it's a flop. Never Really Over peaked at #15, while topping the dance club charts, it reached the top 10 of the adult top 40 and almost cracked the top 10 (11) on the Mainstream top 40. I hope she includes Never really over on the forthcoming album, but still... don't write her off. She is an artist who chose to ignore chart success in an era where most artist delay their albums because Covid doesn't allow them to promote as aggressively. In this time, Katy Perry gives us her music and continues to thrive.