I'm worried about fees going too high when Bitcoin gets mass adopted. (I don't need to explain, 1 block every 10 minutes)

If Bitcoin fees go to $100 or more per transactions, then it's not viable for low and middle class, for mundane tasks like transferring some to someone, DCA a monthly low amount,etc

Layer 2 doesn't seem to be the solution. Layer 2 means risk.
The beauty of Bitcoin is how secure it is to just store your Bitcoins on the layer 1