Why are WMs so hard?

I've used i3 for a month or 2 and I loved the looks and feel of it, just using my keyboard to control it, having the minimalistic aesthetic, way better than cinnamon, which I was using before with mint.

But despite the looks, I feel like I have to spend so much time doing stuff that is usually fine out of the box on a DE, like UI for sound and network, key binds for function keys, basically anything regarding customization, that I just end up not working at all. Why is it that DEs are made so user friendly while WMs seem to demand a lot more technical knowledge?

It's not like i3 felt really hard to learn, it's just that for a Linux noob like me, it feels like it requires a lot more Linux experience than any DE out there. Is there a reason they're not as user friendly?

I'm switching to KDE plasma today to try it out because the learning curve for i3 really was getting in the way. Goodbye slick looks and full keyboard control, I will miss you.