Why couldn't I itemize in 2020?

Married filing jointly, AGI 321,000, Taxable Income 295,102

Turbotax had me file with the standard deduction in 2020.  I contributed charity (about 15k) that year, and had property taxes (about 20k) , as well as some other deductions, so it would have been nice to itemize.  Now I am planning for next year and am trying to understand so that I can plan better.  Why can't I itemize please?