I don’t know how many men use prostitutes, but if there was no market for it, it wouldn’t exist.
In my personal experience one ex told me his mates had paid for him to use a prostitute in Amsterdam for his 21st.
I found out another ex was using escorts when I was using his computer for Amazon and his search history dropped down. He said it was for a friend.
I met someone else who said he had stopped kerbcrawling because he was worried about getting caught and it affecting his professional career.
An old friend started visiting Thailand in his late 40s and is addicted to the cheap sex there ten years later.
Another old friend was caught by his wife having made bookings at two different brothels - peer pressure apparently, age 50 ish.
Add to this the men who have told me they used to date escorts.
Then OnlyFans - which leads to face to face paid meetups
The whole swinging hookup scene - I had a Christian friend who was addicted to Swinging Heaven, I think it was called.
Porn actresses are either paid or trafficked into sex so that is prostitution (or coercion)
Last time I looked at Rate My Punt it was really depressing. I was thinking of volunteering at a charity that supports sex workers.
By the nature of sex work in the UK we don’t know how many men use prostitutes because it’s not illegal to buy or sell sex, only to solicit, run a brothel, I think work in a brothel, pimp women out, or kerb crawl. Saunas and massage parlours are words used to get around the law on working in brothels.
I have had a quiet life with a professional job and these are just the men I know about.