I use Tailscale on everything, instead of opening up ports on a firewall.

I use Mullvad for any unfriendly environments (public wi-fi, cellular networks, etc)

Family members use iCloud Private Relay[1] because it's almost completely seamless.

1. https://support.apple.com/en-us/HT212614

I use Tailscale on all my devices so I can access my "home" computer and the applications on it from anywhere.

My impression with the "VPN for outside traffic" is that somebody who wants to gather a lot of sketchy traffic for monitoring it might just start a VPN service to concentrate it.

I hate to be that guy, but the vast majority of people using "VPN"s are actually using Proxies. A VPN connects a laptop at starbucks to a printer at the office so you can print something. A Proxy forwards requests on your behalf to web servers and returns results. Modern VPNs are marketed as such because people love the "P" part without realizing that... they already had that with SSL.

Isn't using a commercial VPN exposing yourself to the same risk except simply to a different/single provider?

I do when i can. I have protonVPN but then most of the times i get banned from usual sites or get captioned to hell. I kind of gave up, as I believe this is the natural outcome of having real anonymity: abuse.

Yes multiple ones. Trying to get my parents to use one, but guess they are to old to get the concept. Ideas how to explain it to them?

I use a few:

WARP/1.1.1.1, Mullvad, and Blokada on Android

Yep, no.