2 - without prior config only a bunch can do it, like pixels 3 - there's a difference - you can configure wg/ts on a single device(router) and it's done, or you need to do it on 5X+ devices, phones and laptops and fix the configs on all if something changes

I've been able to do WiFi-WiFi connection sharing on my last four Samsung phones as well

Maybe with newer models it's easier, but older ones you needed to go in some advanced settings to allow sharing the wifi, otherwise it'll disable your wifi connection. For pixels it was enough to just enable it from quick menu

I think every single pixel I've ever had could share wifi or 4g/5g.

sharing 4g/5g can be done from almost any android phone, sharing current wifi connection through a hotspot isn't a widespread function