When I went to college in 1993, I was given my grandmother's original Amana RadarRange microwave from 1968 or so, the model with the two dials and the "done" buzzer that wouldn't stop until you hit a button [1]. It was huge, HEAVY, and we joked that it was full of lead shielding, but it got used for three years of college and after that was donated to my workplace when I moved to Austin. As far as I know it kept working there for another 2-3 years, and by then was most likely 25+ years old.
[0] https://goo.gl/photos/qrgoixCJDViks8am9
[1] https://i.ytimg.com/vi/hLhXgVAYoAE/maxresdefault.jpg
Addendum: I just realized that the microwave I have sitting in the kitchen was given to us as a wedding gift in 2001. The clock no longer works properly, but it cooks just fine.
My own oven varies by over 100F plus or minus during regular cooking cycles. This is hugely significant when it comes to baking almost anything. If I put cookie dough in at the wrong time, they'll burn. I do my best to dampen the variability with a baking steel, but a more modern gas oven wouldn't have as much of a range of operating temperatures. Or, at least, a modern and high-quality one.
So, in response to your relatively sarcastic question: yes. Things have changed - not in how we cook, but in the quality of homeostatic controls for ovens.
http://www.xojane.com/diy/oven-calibration-article (technique from cooking for geeks)
Ovens? I guess not unless you go for very very high end.
I'd like to say a few nice words about my induction stovetop though: if anybody is in the market for an electric stovetop the induction based ones are vastly better IMO.
Heats pans faster. Does not heat if there is nothing on top of it. Cools down quicker.
Feels a bit magic.
It still makes toast like a champ.
Convection ovens and steam ovens have become a thing since then. Modern ovens have also become a lot better at keeping a constant temperature.
Also my 'modern' (~8-9 years old) oven gets a lot hotter than my old oven.
(That's Mike from Breaking Bad I think...)
Thanks to youtube and about 30 minutes of work it is working like new again. These days I fix everything myself. Appliances, cars, electronics, furniture, etc. I also try to buy quality instead of disposable but that is getting harder every year.
I also have a chest freezer that my parents bought in the late 1970s and it's still working perfectly as well.
I believe that LG at one point stood for "Lucky Goldstar" as they eventually changed company name and branding.
Ah, from Wikipedia: "GoldStar merged with Lucky Chemical and LG Cable in 1995, changing the corporate name to Lucky-Goldstar, and then finally to LG Electronics."