Cash is even more vulnerable to theft than cryptos. Yet I don't see you criticizing cash.

Regardless, the problem of cryptocurrency theft has been largely solved by hardware wallets and multisig wallets: there hasn't been a single documented case of bitcoins stolen from such a device. Also phone wallets, as long as running on a stock iPhone or Nexus/Pixel with recent security updates, are decently secure. And you can back up the seed of hw & phone wallets, so there is no risk of losing the coins if the device gets destroyed/misplaced.