How "necessary" a microwave may be could depend a lot on your circumstances.

If you're cooking for a "family" with several members, and if you have a regular schedule so that everyone eats together, a good argument can be made that it's easier and just as efficient to use pots and pans. This may also apply if you prefer one or two large meals to "intermittent grazing."

For a single person, or often for a couple, cooking in small microwave portions may be a whole lot easier than messing up a lot of stuff and then cleaning up the messes. The advantages include both the easier preparation of "small portions" but also in easier control of the size of portions prepared.

For many "special diets" needed by those with medical peculiarities, a microwave and a small blender (and an accurate scale) may be necessities, and pots and pans (and a food grinder and sausage stuffer) are just "things in the way."

If you're set up to use lots of frozen foods, the better microwaves are very useful just for thawing small amounts quickly, even if you cook them using other methods. Irregular "feeding schedules" where quick preparation when the patient needs food are a situation that may benefit a lot just for "thawing" stuff that you burn otherwise.

Most things can be "nuked" with good results, but you may have to study up on some of the more exotic methods. Microwaved potatoes can come very close to baked ones, once you learn how many holes to poke through the skin (and how deep) to let the steam out so they're not boiled.

Of course, there are things you can't do in a nuker. (Eggs "sunny side up" or "hard boiled" are NOT RECOMMENDED MICROWAVE RECIPES.)

John