FWIW, debian did the gentoo approach for years. I used to run debian with OpenRC during a time when systemd was already the default. It and other init systems remained fully supported by the distro for quite a while.

Eventually, the pain of supporting everything became too much and debian did go with "my way or the highway", which I supported at the time and still do. I have no idea how that could be "objectively worse", it's very obviously a tradeoff to me. If your packages have to work on any init system, they can not benefit from any particular init system's features and have to work with the lowest common denominator. Every service has to hack around the lack of working state management with pidfile hacks and such.

In my opinion, it's better for a distro to pick any single init system than to try to support them all by limiting all packages to SysV style init scripts. Yes, user choice is important, but that can and does happen via distro choice. Alpine or Devuan are right there if you need them. Linux is fragmented enough, we don't need every distro to be a microcosm of the fractured overall Linux landscape.