There's freeware and cheapware out there. The issue would be the same whether you paid $5 or $5,000 for the license. That has nothing to do with anything whether you believe it or not. 'Adobe's sage advise seems to ignore the fact that we paid $500 for a lifetime license.' Frankly, I wish that I had the option of the Acrobat X interface in the 2017 version but, like Mick & Keith sang, 'You can't always get what you want but if you try sometimes you just might find… You get what you need.' Acrobat Pro X (2010) worked well for over ten years. I opted for Acrobat 2017, a non-subscription 'lifetime license'. Posting 'lifetime license' over and over may gain you sympathy (including mine) but it doesn't change the basic fact that, if you want Acrobat Pro to work over Catalina, you have only 2 options: One is the current stand-alone Adobe Acrobat 2017 the other is one of the subscription plans that Adobe offers. You are not entitled to anything other than your 'lifetime license' not expiring. Unless specified in the license or you purchase a maintenance agreement that guarantees upgrades for a certain number of years, professional software never does. You do have a 'lifetime license' (as you put it) for the use of Acrobat X (or 8, 9, XI, 15 or any other stand-alone version).

Update adobe acrobat x pro mac