I think a lot of his income comes from Patreon, admittedly. Not clear how it breaks down between YouTube and Patreon. The same is probably true for Ben.
What is clear is that most of Shahriar's equipment is not donated, by the manufacturers or by anyone else. He will (obviously) say so when it is, and he rarely does. He buys it himself -- primarily on eBay, but still, that doesn't mean it's cheap.
For my channel, Patreon provides about 2-3 times as much financial support as YouTube ads. If I started doing 30-60 second sponsorships in my videos, that would provide about 5-10 times as much as YouTube ads. I really like Patreon because it's just a basic and honest transaction. I only charge money for each video that I create, and people can give me feedback directly, and increase or decrease their pledge accordingly. Everyone gets what they are expecting.
Tom Scott has a video talking about why he doesn't set up a patreon. My takeaway from that video: one sponsored video covers (for him) multiple months of good patreon income. Given that paying / being paid impacts a relationship, he prefers to keep that for companies instead of changing the relationship with a significant portion of his audience.
It's a good point. If YouTube were my day job, I'm not sure that I would turn down the significant money from sponsorships. If I didn't personally dislike ads so much, I'd probably have already done it. Patreon may not require a huge shift in viewer relationship: Only 1-2% of my viewers support me on Patreon, but even this provides more revenue than basic YouTube ads. The vast majority of viewers benefit from the generosity of the 1-2%, and everyone seems OK with this setup.
What is clear is that most of Shahriar's equipment is not donated, by the manufacturers or by anyone else. He will (obviously) say so when it is, and he rarely does. He buys it himself -- primarily on eBay, but still, that doesn't mean it's cheap.