The World Wide Web was invented only 30 years ago, yet it's arguably the single most essential service during this time. Without it, social distancing while keeping large parts of the economy alive wouldn't have even been an option.

At the rate technology is becoming embedded into our daily lives, I think an arbitrary number of years is definitely not the way to decide whether something is essential. Context matters. What if instead of a pandemic that affects the lungs, the next one affects older people's ability to walk? Not very hard to imagine Uber being considered a 100% essential service at that point.

Useful? No. Effective? No. Meaningful? No. But definitely simple.

By those measures BTW, antibiotics, modern sewers and (for the most part) vacinations aren't essential.

And indeed they aren't, for the survival of the human race. They are, however, very important for the survival of individual humans.