Bootsplash was an experiment from SUSE. They wanted to have an alternative to plymouth. I was also looking for some similar and got in contact with the author. Back then he developed it and I did some tests and usage. SUSE never shipped it as plymouth was in the end good enough. Also the vendor logo support was added at some point. Bootsplash works fine on the original Pinephone but broke for some reason with 6.2 kernel on the Pinephone Pro.
Also upstream removed some part to make Bootsplash work, hence I had to revert some stuff to get it work still. So yes bootsplash itself is not maintained but still works in some cases.
We can now argue if that is meaningful or not to have it.
It matters because dropped packages don’t get removed from installations.
That package obviously isn’t maintained anymore and it’s old/aging contents might cause all kind of glitches/problems in the future if someone still uses it (because it was installed and used by default on KDE installations in the past).