I'm probably going to try a small scale signature campaign for a project I'm working on. Personally I don't like how most ICOs just buy a massive amount of signatures based on members ranks on the forum. In my mind it's cheaper, and probably more effective to get a few members who post quality stuff and close to the niche of the project.
Another thing why you might think that signature campaigns have less value (and I'm not claiming they aren't mind you) is that we are in a bear market and have been for a long time.
Payment would not be so high if it did not work. I know personally the Bounty manager, who, just like you are convinced that the time of subscription companies has gone and he does not use it in advertising his work projects.
I disagree that payment wouldn't be high, even if a signature campaign didn't work. Many times people have no idea if something will work, but think that if everyone else does a signature campaign, it has to work. So they too invest in a signature campaign, keeping the price of signatures high. Doesn't mean that projects got results from signature campaigns though.