I was under the impression that the $10k cap is for SALT and mortgage interest is separate? The mortgage interest deduction was reduced, interest on new loans is only deductable for the first $750k of debt, instead of $1M, and mortgage rates were really low in 2017; capped SALT + a relatively low interest rate on $750k might not combine to more than the standard deduction if you're married filing jointly. Certainly on my ~ $350k mortgage @ 3.15%, I stopped itemizing after the tax changes.

The bigger change for mortgage interest was the massive increase in the standard deduction in 2018 to $24,000 from $12,700. We were barely doing better than the standard deduction prior to that, and the increase put us pretty far into "just take standard" territory.

Absolutely not. That's property tax, not mortgage interest.