Question about Lightning Network

I'm not sure if I fully understand the concept, but isn't it a problem that you have to "deposit" BTC into a channel for future use?

The typical user might want to just buy a $3 coffee/online product without exposing $100 to future volatility.

Even ignoring volatility risk, a lot of people live paycheck to paycheck and wouldn't want to lock up any money. Are one-off low value transactions unfeasible with LN?