In the UK, deductibles on mortgage interest payments (known as MIRAS[0]) was abolished for private home owners in 2000. As a renter this kind of always stuck in my craw that homeowners got this preferential treatment and was quite glad it was abolished (even after becoming a "homeowner").
Oddly, buy-to-let landlords do retain this deductible, though HMRC have fiddled around with how this works over recent times[1].
Yes, the BTL sort of makes sense though if you view the mortgage as a business expense, but BTL has had a distorting effect on the UK housing market for too long - changes are desperately needed here, but with so many Tory donors being housing firms, it's unlikely to happen.
Someone on PAYE will have most of the deductibles handled by their employer (pension, any salary sacrifice schemes etc).