I've cooked various cuisines at home for decades, including a stint in a professional kitchen.

I'm not suggesting you microwave your shumai dumplings or your egg custard.

But for your standard fibrous veggies like peas, carrots, broccoli, cauliflower, lima beans, etc.?

Yes, frozen plus microwaved vs. steamed yields identical results, provided you stir in the microwave every minute to avoid building up hot spots. It's just physics.

Ok you've added 'fibrous' now, and to be honest of that list I've only steamed peas, but quickly realised I prefer boiling them if nothing else than because it's easier.

I tried kale in the microwave once (with a bit of water and covered in cling film (seran(?) wrap)) and it was awful.

To me at least 'stir in the microwave every minute to avoid building up hot spots' just isn't easier, I only use mine for defrosting/reheating things (I live alone so there's always multiple portions left over).