1. Fair enough.
2. Most Android phones can do this.
3. Android phones can do this.
4. This is just the same question as 3.
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
2,3 and 4 android can do. 1 is very fair but could be achieved with an old phone, maybe with a rubbish battery plugged in.
What if you want to use the hotel's internet connection instead of your roaming data?
What if you want to use wireguard or tailscale to funnel all traffic through your home network?
What if you want to enable your family's devices to connect to your self-hosted services?