And what bad do encrypted text files have? Like txts in rars. In a PC that no one ever touched you download Winrar and add to archive the csv file of the private keys. You put a very strong password that can remember. And you save it to different places with a name that isn't suspicious.
Are you doing this on a permanently airgapped computer (i.e. one which is never connected to the internet) with a clean install of an OS? You've just said "download Winrar", which makes me think the answer is no. To add your private keys to an encrypted archive they must first exist on your computer in plain text. Malware can copy those keys and transmit them to a third party now or at any point in the future when internet access is re-established.
There is a reason that every good wallet tells you to back up your seed phrase non-electronically by writing it down on paper.
So.. Same thing with software wallet? But you have to be careful.
Not so. If your software wallet is lost or stolen, then for the majority of cases it will be significantly easier for an attacker to extract your private keys than from a hardware wallet.