I'm a married guy and in my opinion it doesn't looked normal to me.
It's most likely related to his unsatisfied sexual craving/fantasy.
This is also related to you as his wife.
Probably there's lack of sex, or boring sex or you no longer dress nicely?
Increasing 2k to 4k is really a lot, and browsing all these on daily basis (how many hours are needed to go through that lengthy list??).
Imagine screening resume for interview also in hundreds only...lol.
To solve this issue, pls don't just blame on his sexual craving/fantasy.
He needs to tell you why he needs such visual stuff everyday and you need to be prepared to help him to overcome all this (eg. if he feedback lack of sex or the sex is boring, etc).
Don't push him away, but rather work together with him.
Acknowledgement is the 1st step to solving the problem.
And i would see the similarities between all the girls that the guy follow.
Do they share same characteristic? Or same pattern of behavior? Maybe that will tell what he is looking for and ts can try to match.