Not sure if I used the correct terms but what is the difference in security and privacy between downloading from a public wifi (or a closed wifi; with password) and mobile hotspot (sharing 4G/5G data from your phone to your computer)? Which one is recommended or does it not matter?
Is this similar to vLAN that could be configured in my router but I never bothered since it was overkill for me?
You can achieve a similar thing using vlans - usually by default they’re isolated but you may add specific rules that allow traffic between vlans if it meets certain criteria (specific ports, specific types of traffic, traffic to or from specific hosts, any combination of those). So yeah you can imagine client isolation being like having each client on their own vlan - except without needing a different subnet for each client.