Is it really a problem? I don't understand this mindset. If a person offers value to a company (and vice versa), there's a mutual benefit. Why should either party be forced or coerced to stay in business with one another? Employees may just as much leave on a whim as they could be fired or laid off. There are bad people all over the world. The best option is for this employee to start looking ASAP. Once they have a solid job lined up, they could then submit their resignation. In the letter, write a detailed response as to why they're leaving.
Jobs are not hard to come by right now. Outside of tech, there are places hiring left and right. It's a madhouse, and not only minimum wage things people criticize. There are some great paying jobs out there in the trades. People are needed badly.
> Please consider most people aren't in that position.
Many people could (and should) plan, but choose not to. It's wise for anyone to set aside an emergency fund. The concept isn't hard, but the discipline is, whatever the cause may be.