Like everywhere in the world, it still depends on where you live. In capital cities, the working people sometimes live alone in their own/shared apartment, so cooking for yourself is less preferred since food stalls are affordable and almost everywhere.

But in small cities or villages, you usually live with your main family or even your big family, so it's cheaper to cook in large batches at home everyday.

I'd also confidently say (I'm Indonesian) that almost all house has a rice cooker, so you could count that as cooking right?

A lot of my friends and colleagues in Japan rarely cook at home. Food from convenient stores, supermarkets is often good, cheap and healthy here

perhaps in mega-cities and as far as the young generation is concerned, eating out multiple times a day is not uncommon