I used window managers for years, but the hurdle of actually configuring stuff not-related to the WM itself (like setting up dark mode) made me switch to a full-fledged desktop environment. Thanks for mentioning Noctalia - it looks like exactly what I needed!
I was in the same boat, and I ended up running this: https://danklinux.com/
It works a charm.
I was on the same boat as you. I installed noctalia after having tried and not really getting a perfect arch / niri / waybar setup.
I think I'm completely done after like 6 hours which is insanely fast, and it really is everything I ever wanted. It is cohesive, easy to style, has good defaults, includes essential programs like polkit agent and notification daemon / osd, has a ton of plugins.
I should have tried it so much sooner.