How do I put this.
If you browse for a tag and all you see is visual novels, then, well, then this tag is obviously very popular for visual novels.
Of the ~900k games on itch, only 26k are tagged visual novel. There are 130k platformers. And only 350 games combining those two.
On the itch landing page, the two most popular tags are horror and visual novel. What does this mean? It means that developers that want to tag their game with popular tags might chose those tags, if they apply even remotely.
And it means, that the top of the popular browse will be populated with lots of those games. It should thin out a bit on the following pages.
You could also try the recent pages. But beware, lots of malware there. Be suspicous of "new" games. Use sandboxing (the itch app can set this up). The current filtering of itch is either broken or hopelessly overloaded, so there are still dozens of games getting through. They are uploaded on hacked accounts, so not even payment active is a green flag.