Why is food so much worse after being frozen?

I wonder does the method of reheating frozen food make a difference. Presumably most people reheat in a microwave but wonder would reheating slower in an oven make any difference to taste/flavour?

Convenience, saves having to go to the shop as often for some. Butter also freezes fine, either real butter or spreads in tubs, all fine in freezer.

Actually when my father was alive I bought a small second hand extra freezer for his house and filled it every two weeks or so with milk/bread and some spreads. It saved a lot of shopping on a regular basis for the essentials.

On the reheating query, the microwave is fine if you do it right. For example something like mashed potato should be heated in a glass bowl with plenty of room and given a couple of stirs while heating and should be well fluffed up again and then it will be like fresh. Where it's horrible is if you just heat a scoop of mash say on a plate until hot and eat it as is, it's always a bit firm and you are slicing off bits rather than having lovely fluffy mash, you must mash it up again which distributes the heat better and lightens it. Also when freezing it make it tasty, plenty salt/pepper, bit of butter and I like some green onions too, I also don't mash as such but use an electric hand mixer to make nice fluffy mash

I'm eating almost exclusively from the freezer these days with a few exceptions. I haven't been shopping since early last week and won't be going for at least the two weeks of lockdown we have. Fortunately I had well stocked up weeks ago with milk especially which is what it seems most people have to go for regularly. Bread I can make as needed and freeze some as well.

Only thing I don't have is fresh fruit but I have lots of frozen berries and some tinned pears and can use them for several desserts Loads of stewed apple too from last years crop of apples.
Not much in the line of salad either but can live without that!

I bought potatoes when they were a Lidl special weeks ago and froze mash and potato wedges, still have some left and want to use up cream so will make garlic/cream potato and freeze that in portions. If you have a bit of smoked salmon it's delicious layered up between the layers of potato too.

I bought lots of mince and have some frozen raw, more frozen as burgers (burger buns made and frozen) and some cooked into meat loaf and frozen in slices to provide quick dinners. Yesterday was mash/meat loaf/cabbage, cooked fresh spuds in but rest was frozen. Cabbage was cooked in a saucepan with little water/knob of butter and meat loaf heated in microwave. Microwave is not the answer to all reheating, some things do better other ways to make them taste as fresh. I will run out of lettuce/tomato for my burgers but like onion/gherkins on them too so plenty of those.

I also have a lot of chicken fillets and pieces, I get a txt from local butcher with specials and the week it's chicken fillets I usually buy 20, I freeze some whole, some I flatten and stuff and roll up in bacon, I cut some into pieces and freeze them loosely on a sheet of parchment, when frozen then I pack them in bags so I can just fry as many as needed straight from frozen for a curry or stir fry, always have peppers chopped and frozen and celery for curries/stews.

All this is no good of course if you don't have a decent size freezer or two and probably too late to buy one anywhere.