I've got friends who have lost so much money from trusting rewards and giveaways. Really not worth it unless it comes from a legitimate source; Blockchain.com, Coinbase or BAT rewards etc.
That's just greed, you must be talking about those scam ETH giveways on twitter. I strongly believe only greedy fools with mindset of earning quick & free money (Ponzi scheme business) fall for those type of Scam. From the name give-way they're supposed to understand it's meant to be free if it's truely a giveways and anything that involves putting xx amount of coins to get xxx amount in return is just pure Ponzi which means scam and should be avoided. Good they learnt their lesson though.
No we are talking about legitmate coins getting their websites cloned and added onto airdrops.io with a GoogleForm asking for private keys. There not that stupid to fall for giveaway scams on Twitter. I'm talking about state of the art copying and email phishing on BIG PROJECTS.
Also. I know someone who got 5 BTC removed from their Trezor wallet. A legit upgrade came up, his computer was phished. Crazy huh.