I've invested in over 100 startups through syndicates on AngelList in the past few years. It's not possible for a syndicate lead to steal the money. AngelList collects directly from the investor and wires directly to the company. Plus I've been paid out 6 times from exits.
But you can definitely make bad investments, just like on Robinhood. Except in angel investing, odds are you're never going to see that money again (like 1 in 20 startups makes it).
Also try to remember that you and the syndicate lead are most likely a tiny check to the company, so you aren't getting information rights. You're essentially just along for the ride. Buckle up.