For me, at least, it's the fact that he's scamming people out of their money. He's a manipulator, and he's manipulating people out of their money. And the part that really gets me is that he gets away with it. No one's investigating him. No one's bringing him to account. We can see the lies and the manipulation, but no one in power is doing anything about this guy.
It's not necessarily the scam, but it's him getting away with it with little repercussions.
I wouldn't say there's little repercussions. I mean, at the end of the day he's still DSP.
I agree that DSP is a liar and a manipulator. What he does is absolutely a scam. The thing is, I don't think DSP is particularly successful at his scams. In fact, it feels like the more DSP actively tries to pull cons, the more he alienates the people he's trying to scam. As others have pointed out, it's not like Phil's whales were going to spend the money they donate to Phil on anything meaningful. It was always going to go towards him. At most, Phil is speeding up the process.
Phil's whales have their own weird reasons for hanging onto Phil. Some of them are probably just lonely dudes who want to pretend Phil is their friend. Others live vicariously through Phil. They want to spite the detractors because it gives them a sense of power and lets them pretend they are doing something meaningful/make up for their own inability to spite the people they dislike in their lives. Basically, they latch onto Phil because he's pathetic, which makes him relatable to them. It is also worth noting these weird whales aren't limited to Phil. Other Twitch streamers/YouTubers/online personalities get them as well. Phil's are a little more extreme in the amount they drop which is part of why he's so infamous to begin with, but I've seen other people throw a surprising amount of money at their internet personalities of choice. I'm sure Tevin has some of these types of people as well, he just hasn't been lucky enough to land a consistent whale to the best of my knowledge. But, I'm sure he has at least some people that are donating just to spite Phil/his paypigs.
Now, there are some paypigs that do start off believing the lies at first, but they tend to catch on when Phil actually tries to pull a scam. It just isn't as noteworthy because they're relatively "normal" at least as far as Twitch viewers go. They don't participate much in chat, get overlooked because their donations are smaller/more spaced out and not worth talking about. Them leaving is also not particularly noteworthy for the same reasons. It has had an impact though. Even if it hasn't financially destroyed Phil, if you look at his Patreon/views/even his general tips/cheers before a whale steps in, it has an impact.
The (somewhat) TLDR is that Phil, much like most things in life, fails at successfully conning people. The real reason he gets money is he's pathetic and attracts a similar pod of whales who project onto him. He's still absolutely a bad person for trying to run the cons in the first place, but I think they ultimately do more harm than good, at least in the sense that Phil could arguably make more/live a better life by simply improving his streaming setup and trying to become a better person (which is arguably impossible at this point) but he keeps taking the lazy/greedy way out and goes for the get rich quick scheme. I will also say what Phil does isn't sustainable, at least compared with the way he lives, and I don't think it is a stretch to say he's too stupid/stubborn to change his lifestyle. His downfall is by no means around the corner and I bet he can keep going for years, but I do think he is struggling behind the scenes, again because of his own greed/stupidity. He is and always will be his own worst enemy and that's why even with a stacked deck from his loyal whales, he remains a sad and bitter hermit. If you feel yourself getting mad at Phil, just remind yourself that the price for his "success" is having to be DSP.