Those hacked together system-specific bash scripts were shit.
With a different feature set per script as well. The systemd service files have often been pushed upstream.
Pretty sure people liking those scripts never really tried dealing with them across distributions. Though this just rehashes things that were said when distributions decided if to switch to systemd. Still the same strange claim that those scripts are somehow easier. It wasn’t, it is also way easier to package a systemd file from upstream than to maintain that stuff within a distribution.