Use Alpine or something then. I use Alpine as well on a server, OpenBSD on a server, slackware on a server, slackware on my laptop... There's some options. We even use Devuan to host OP's essay, although we'll eventually move to openbsd probably for other reasons.

In terms of package management... why do you need it? I have no problem maintaining everything with slackpkg and sbopkg along with slackbuilds.org. Sometimes it takes a while to find all the requirements for an application and add them to a queue, but once it's set up it's just sbopkg, click on update, upgrade, and you're good. It's pretty much rock solid once I get everything installed and I haven't missed package management much at all. My main gripe is the old packages in 14.2 but -current has a lot newer stuff. I don't mind waiting though.

It's 2020, and nix and guix both run on top of Slackware just fine.