Can't Install new software on Mac. Says I need a higher operating system. Yet there are no updates available on my Mac. you have got to be KIDDING ME!!!

The 2019 software is a new product that requires Mac OSX 10.13 or higher to run.  The Apple development tools (Supplied by Apple) and Apple has drooped support for software development for any OS before 10.13.

I agree.  This is FRAUD on the part of intuit - selling software that THEY KNOW won't work!!!