Basically all of them are botnets, yes. They generally claim to have consent but I'm pretty sure 99% of it is "some app the user uses has it buried in a 200 page ToS"-style consent.

Nope, they’re different things. Proxy networks like Proxybase [0] use open-source clients and ask for the user’s consent before allowing them to join the network.

[0] https://proxybase.xyz