You can very well lose all of your crypto balance by sending it to a wrong wallet address. When it’s this easy to lose everything, there’s no way for cryptocurrencies to become mainstream (at least as currencies).
Handling private keys, smart contract, wallet addresses in itself is very low level stuff. To enable mainstream adoption, suitable abstractions like smart wallets + recovery options + intuitive UIs and (for better or worse) third-party custodian solutions would be required.
Ease of pump-and-dump schemes
Crypto allows you to operate multiple wallets: What’s to stop you from buying a property/assets, selling it to yourself a dozen times at spiraling valuations, hiring a PR agent to place breathless stories in the press, and then selling it for 5,000 times what you originally paid? BTW, nothing in the system stops you from doing this. Indeed, the anonymity of blockchain encourages it. (Classic example- a NFT sold for $532 million)