Don't believe everything you see.
A lot of those influencer videos where they give stuff away are either sponsored (so the prize is paid for by the sponsor) or it's given out to friends/actors, who are in on it and get paid money but not necessarily the prize.
I can't speak for Mr. Beast specifically, but I know of many influencers that do those "I'm giving away a house or sports car" that are completely view baiting. The luxury prize is leased for the shoot and/or people are offered a sum of money or a lease on the item.
e.g., would you rather I pay you $10k in installments now or we can pay for for your lease for 6 months on this sports car? Most people will take the lump sum.