Binance is the best by a wide margin right now. Most stable, good tech, great job scaling, and lowest fees. The crypto market moves very fast though. “Standing the test of time” isn’t really a thing.
None of those things tell me Binance is safe. Binance is not even a year old! Low fees and the fact that their servers haven't crashed yet are hardly reassuring. Being based in China doesn't help me trust them either.
They are based in Hong Kong which has a different set of rules and legal system than mainland China.
Indeed, safety isn’t really a thing in the crypto market either.
I don't know about scaling, at least technology wise. Their trading web interface maxes out my CPU core at just 4-8 tx/s. And that's usually the time of big movements, exactly when you don't want trading interface to freeze up on you.
It also has an ERC20 token so you can become a stakeholder in its success.