You dont need to actually and if you do find that Hardware wallets like Trezor and the rest then you could still able to hold up your wallet but not on the same where these HW does.
Honestly, after all the years i've been around on this space which i didnt able to buy one even if im capable on doing so. I do make out some storage on a non-custodial wallet
like Electrum since we are talking on Bitcoin on here and some keys on Trustwallet or Myetherwallet which i do make some list on a notepad and saving up those keys
but of course you should really be that mindful on where you do put up those usb sticks or flash drive because on the time that
it would be exposed to other people and plugged it in, then say goodbye into your funds.

We could be able to differentiate on what are the advantage on having that HW though but since you cant really be able to afford then having that USB storage of keys
would be that sufficient but if you do have the chance on buying one then its better to do so.