You think that a fridge is about 'keeping food cold'?
It's about ease of access, price, noise, convenience, durability, features.
My folks have this fancy 2 door thing, perfectly quiet, makes the best ice you can imagine, it's hidden into the cuppboards, it's energy efficient, has these crisper things, you can see in and reach around easy, lots of space. It's a better product.
Energy efficiency is nice, it's a good improvement, but from an end user perspective the 30 year old fridge still keeps your food just as cold.
If you were from 2025 and got trapped in the 1970s and needed to keep some milk from going sour for a day, you wouldn't be thinking "damn if only these old 1970s fridges worked more efficiently. I could easily accomplish this goal with a modern fridge!"
The 1970s fridge would do just fine