I know my own taxes pretty well. I don’t follow the tax code changes but could fill out a 1040 form on my own. Even did for a short time.
I use tax prep software because I do NOT want to worry whether I copied the amount from line C to line K correctly. The IRS forms are a nightmare!
The postscript in PDF should allow something more sane than what we have today in IRS forms, but that’s just wishful thinking.