r2modman is just an alternate frontend to Overwolfs nonsense and basically exists on the grace that most people install Overwolfs launcher (Thunderstore, which confusingly is also the name of the repository hosting the mods - my understanding is that the original devs of Thunderstore sold their repository to Overwolf) for it instead of r2modman.

As implied by negativity in the prior sentence, Overwolfs stuff is pretty awful to use; compared to r2modman, it feels like you're installing a PUP instead of a mod manager. There's lots of ads and it's pretty clunky to use.