My first order for a license is from 2001. Later one in 2009 and as a gratitude I just ordered new licenses for the company. Continued development should be honored, even if developers don't force you to pay.
With the new version 5.8 they moved to a 64-bit architecture for compatibility with macOS 10.15 Catalina and added support for Dark Mode on macOS 10.14 Mojave and later. More in the release notes here.
This is great news as this is one of the applications we waited for to support 64-bit before using macOS Catalina (next year).
PS: I also use transmit sometimes, another great app where I also have a license.