Not a digitizer issue - that would cause the screen to appear normal but not respond.  (And the S-Pen would work - that's not done by the digitizer.)
I'd guess, without actually having the phone, that it's a motherboard issue.  Does it pay to repair?  Depending on the carrier, that can run from $50-$130 on eBay - plus labor.  But you can buy one on Swappa for probably less than the repair bill.