I've been using Puppy, off and on, very happily since version 2. This note is not intended as a criticism but rather as a positive recommendation for the future.
What I see happening is this ...
Back when I started with Puppy, it was very challenging to run a good solid linux distro on a 5 to 15 year old computer. Puppy elegantly solved this problem for the world. It revitalized the old computers of the day.
The trade-off was that the desktop GUI (JWM/Rox/etc) was somewhat more primitive than today's more popular mainstream interfaces (Xfce, Mate, Lxqt/Lxde, etc). With JWM/Rox, it's more difficult to alter the taskbar, change the desktop icons, perform common file operations without copy/paste, etc.
That was necessary and good because you simply couldn't run a more capable desktop GUI on older equipment... it required too many resources.
But today that is no longer the case. You can easily run those more sophisticated interfaces like Xfce, Mate, Lxqt, etc on an older computer without noticeable loss of performance.
For example, I dual-boot Puppy and Mint/Xfce on all my machines and those I give away to charity -- which are 8 to 12 year old Intel Dual Core boxes with 2 to 4 gig ram. I see everyone choosing to use the Mint/Xfce install these days because the desktop GUI is easier -- you can easily alter the taskbar, change the desktop icons, copy/paste for file operations, and more.
So here's my point. The more resource-light JWM/Rox interface is no longer necessary. If Puppy had a more capable desktop GUI -- like Xfce or Lxqt -- it would be much popular. The public now expects that easier desktop GUI. And Puppy would not lose any performance capability in terms of the 5 to 15 year old computers that are the sweet spot of its user base.
It's 2021, and old computers have grown up. I'd recommend a Puppy with Xfce or Lxqt interface. It would continue to achieve Puppy's goals -- while making it much more popular.
(thanks for listening, and sorry if this is posted in the wrong place...)