The wallet.dat File: When you ran the original Bitcoin software on your desktop computer, it downloaded the blockchain and automatically generated a local file named wallet.dat. This single file held your private keys. If the file corrupted or the hard drive died, your funds vanished. Except you backed it up somewhere else like in a paper or something.
You can't backup a .data file on a paper , it can only be stored digitally. On the other hand you can make use of paper wallet which can be easily backed up as it only contain a private key and the corresponding pub. address
Abeg, how do you see this custody thing now? Are we rushing too much for convenience and handing our keys to centralized platforms, or do we actually need these easier tools?
Which easier tools?
Self-custody isn't really that hard once you understand it. What people are afraid of is taking responsibility for their own money. The only challenging part I can think of for most people would be setting up cold storage if they want to completely go off the grid. Using a non-custodial wallet itself isn't that hard.