This isn't an attack, I am genuinely curious, what makes you think that their hearts are good? I think quite the opposite.
I think they show their viewers utter contempt, take them completely for granted and eventually, it is going to backfire on them spectacularly.
They don't interact. They have all the time in the world to reply to comments, it would take them seconds and even a simple like would make the day of the poor souls who think S&D are something to aspire to, yet they don't do it because they feel like they don't have to, same as they don't have to have jobs.
Their attitude towards gifts they receive, whether from fans or brand. If they were nice people, they would be grateful for anything, and would make sure they devoted plenty of time in the vlogs to show off whatever they had been sent. Instead, they open the PO Box and after showing off their first haul Sophie made a point of saying they wouldn't necessarily always show what they are sent. Not even attempting to hide their greed, 'send us pressies but don't expect anything in return'.
Super chats. Any decent person would turn them off, surely they know that those most likely to give are vulnerable themselves and attempting to buy S&D's affection!? Yet, they take they money anyway.
I never believe any of the gushing over how grateful they are to the fans is genuine, I find them incredibly insincere, which tickles me as Dave is supposed to be an actor