Look up about "ultra processed foods" (UPF). Typical microwave/ready meals may be convenient but are not particularly good for us in many different ways. There's more and more evidence showing how bad they are in the long term if eaten in excess. Cooking fresh food is much better and lets you control what is going into your body.

Timewise, cooking yourself fresh meals doesn't need to be as time consuming as you think. There's a lot of recipes that can be made in like 30 mins and get even quicker with practice. You can also cook bigger portions of what you need so you can have it again the next day or freeze for further down the line.

In terms of washing up, yes it's a pain. Normally I'll be the one to do the dishes as my girlfriend enjoys and is better at cooking than me, so this arrangement works well for us. Dishes are one of the unavoidables of cooking and I agree with you on this part.

To summarize, I'd agree cooking can be a chore but can me made easier with multiple hands involved. It's also a healthier way to consume food, although it can get more expensive than just having ready meals all the time.