Here's the point: Let's say you're married and file a joint return. Unless your itemizable deductions for 2020 are greater than $24,800, itemizing isn't worthwhile.
Further, in order to deduct all of your mortgage insurance payments, your adjusted gross income, or AGI, needs to be less than $100,000. This is the same for all filing statuses except "married filing separately," which has a cap of $50,000. Above these thresholds, taxpayers lose 10% of the deduction until it disappears completely above AGI of $109,000 and $54,500, respectively.
The key takeaway is that most taxpayers use the standard deduction. And a disproportionate amount of those who itemize have incomes over the $109,000 AGI threshold to be able to use the deduction. So, the short answer is that unless your total itemizable deductions are less than your applicable standard deduction and your adjusted gross income is under $109,000, you won't be able to deduct the mortgage interest on your primary home.
A note for investors
It's worth pointing out that real estate investors may be able to deduct their mortgage insurance premiums, even if they don't meet the qualifications discussed earlier. In the case of a rental property, mortgage insurance premiums can typically be deducted on Schedule E. However, it's important to note that the vast majority of rental property mortgages don't have PMI, as it is very difficult to find a rental property loan with less than 20% down.