Is a heated bed an essential component for printing (difference between Creality Ender 3 or Anycubic Mega Zero)? I have two options - to buy either the Ender 3 or the Mega Zero. I'm heading towards Ender 3 because the Mega Zero doesn't have a heated bed. 

My question is, how is a printer without a heated bed (the Mega Zero) a better option than one with a heated bed (the Ender 3)?

Why would I even consider buying a printer without a heated bed when the Ender 3 can do the same things and has a heated bed? I want be able to print not only PLA but other materials as well. Doesn't the Mega Zero limit you to using only PLA?
I used to print PLA with my heated bed turned off, since it was deforming when heated.

It works perfectly fine, only detaching the print was terribly difficult.

I would not buy a printer without it, because even a weak bed reaching only 50°C gives you many more possibilities.

I mean, you could use it to keep your coffee warm while you work at the computer, or to warm up chemical solutions to make them react faster. You can also use the bed to shake the solution!

Go for a heated bed.