I've had nothing but great experiences with Stubhub. Got excellent seats, WAY below face value to the first Broadway previews of The Great Comet and Dear Evan Hansen for $50 each about 2 hours before curtain.
I managed to get a pair of SITPWG tickets 3 hours before curtain at below face value. Anything like Hamilton I would avoid, the rest I would say are genuine tickets. Worst case if they are, Stubhub offers full refunds for tickets that prove to be counterfeit.
I had never heard of Tickpick before I used them for Hamilton tickets - at the height of Tony hype when I was really worried about fake tickets. Took a chance bc they offered the same guarantees as StubHub and charge sellers lower fees so the prices for buyers are often a lot lower. I had no problems with my tickets and have used them since. So I'd check tickets/prices there as well.
Also if you can find hard tickets vs PDFs, you can feel slightly more secure about their validity.