If I am being honest, I knew it was pointless before I started because I had already narrowed down my main desktop to only two distros. I had four at one point but it was just more to keep updated.
I did it because I thought it would be a fun project. It was actually more fun than I thought it would be because I learned a bunch about btrfs and certain distros that I didn’t know before.
We all have our weird ways of having fun: some of us setup multiple different distros to share as many btrfs subvolumes as possible, some of converse with frogs in Middle Egyptian. Who am I to say that the former is crazy, while the latter is completely sane? 
Well, of course this whole exercise is pointless from the usability viewpoint: Linux is Linux (for the most part): pretty much any distro can be made usable and almost indistinguishable from pretty much any other distro. It is still impressive what you managed to do here.
However, if you enjoyed doing it that alone makes it not pointless, just like watching a movie, playing a video game, or reading a book is not pointless. And if you learnt something while doing it, that’s even better.
As long as you enjoy what you are doing it’s worth the effort. 
So I have been looking for a distro for my wife’s laptop. Her computer use is substantially different than mine and I the problem I usually have is the distros I am the most familiar with and find the easiest to support are the not the ones that are the best suited to her needs.
I was thinking that Pop! OS might be a good fit for her so I thought I would try it out and see how it is. Naturally I added to my laptop. Unfortunately, that was the proverbial straw and I filled up my 1GiB EFI partition. Fortunately, I apparently planned for that as I left empty space between the EFI partition and the BTRFS partition. A quick partition expansion later and now I have 7 distros.