It is essential. It will help you remain calm if bad things happen: job loss, catastrophic illness, other emergency. It’s often recommended that people bank enough that they can survive for six months without income. That’s a good goal to strive for. You have to treat it as what it is meant to be, however, and not “dip into it” for non-essentials like holiday gifts or such.
Many are wondering how they’d sock away that much, they live paycheck to paycheck. That is a dangerous way to live and I doubt people “choose” it but they should seek out ways to save: for an emergency fund, for retirement, for known future expenses (college for kids? a new car? replacing the refrigerator, etc.).
The one thing we know is that there will ALWAYS be unexpected expenses. Some are emergencies, some not, but odds are good everyone will be hit with a big expense at some point.

È una buona idea nel mondo che cambia costantemente. Lavoro, scuole, educazione, famiglia, casa, bollette mediche, bollette, ecc....... Potrei continuare.