Jackbox is a multiplayer party game, so they'd be paying to play with Phil and post detractor memes. Honestly, it's not a bad idea. Well, charging that much specifically is a little much, but it's something that gets thrown out here every so often. The big reason Phil would never do something like that is his pride would never allow it. Jackbox especially is rough for Phil because he can't blame input lag or faulty controllers or anything else, it'd just be a string of people insulting Kat, telling him to get a job or bringing up the masturbation incident.
The smart and as Phil would like to say, "interactive" way to do something like this is have certain days where you do multiplayer games with your subscribers. Could give higher priority to higher tiered subs, going through the 3's and 2's before you get to general subscribers. Having it done through subs is less of a cut than just setting a certain amount for donations, but it keeps trolls from just cancelling the PayPal transaction after a match. Normal streamers do that as a way to play games with their fans, but with Phil, you know there'd be detractors willing to pay money just to destroy Phil in a game, especially if it was being restreamed by Tevin.