VPN on laptop or phone for secure hotspot connection?

VPN
1

When my laptop is connected to my phone’s hotspot, on which device should I use my VPN to secure the connection?

3

Thanks! So only running the VPN on my laptop should be sufficient then?

4

And a VPN when connecting to my hotspot will basically only mean that my mobile ISP can’t see my activity? Are there any other reasons to still get a VPN when connected to my own password-protected mobile hotspot?