I am exploring all options safe or paid to store coins or to mine it. I have heard people saying that trezor and other hardware wallets are also not fully safe?
100% safety doesn't exist... However, there's a huuuuuuge
256 difference between using an online wallet and a hardware wallet.
Sure, in the past certain attack vectors were found for certain types of hardware wallets, but afaik, those attack vectors were always rather far-fetched. Usually, the attacker has to have physical access to your device to begin with.
There is a big contrast to many other types of wallets, with attack vectors including: "not owning your own keys, phishing, software vulnerability's, seed phrases being sent to a remote server in cleartext,...
It's not because a hardware wallet only offers 99,99% security you should ever consider using a wallet that offers 50% security because 99,99% isn't 100%*
*numbers only shown to make a point, they are not based on measurements...