The top of a refrigerator is an easily accessible location for a feline.

Additionally, putting any expensive gadget up high above a hard surface is a recipe for disaster.

Both my cats get up on the refrigerator easily.

There's this joke that goes something like this:

- What's the highest a cat can jump?

- [... no idea or wrong answer ...]

- How high do you store your food?

Vid of a cat jumping over 1m90 high:

https://www.youtube.com/watch?v=Mw7CURpGRmw

2 of my 3 cats are quite regularly on top of the refrigerator. One likes to nap up there, and the other likes to experiment with gravity by knocking magnets off the fridge. The only reason the 3rd doesn't get up there is because she is almost 18 years old and has arthritis and can't jump anymore. When she was younger she would use the fridge as a stepping stone to get on top of the kitchen cabinets and regularly nap there. There is no such thing as a cat-proof vertical height.