What do you think is the most important thing for customer support?

All of them are important. If all is working well, would you still want them to contact Customer Support? If not, then, Time to Resolve (TTR) is one of the key metrics.

Empathy. They might respond arrogant, angry and quite disappointed with our responses or multiple levels of transfer (I usually experience this with Amazon and I'm not a fan of this). It's up to our brand value how we react. One of the things I learned from my recent experience working at a startup is that we need to acknowledge why they communicate like this. If it's understandable empathy is the only thing that will retain the user to some point. And for the next some people are born arrogant and there will be always a demanding tone in their voice. That might hurt our mental health if we're a small business trying to do everything at full capacity.

In my opinion it's problem-solving skills that are important.

Listening properly and replying straight and accurately to what the customer is requesting. Speed is important but quality but the response is definitely more important. This is always what I suggest to my team, I rather prefer have a customer that wait for a few more minutes, rather than going too fast and giving an answer that doesn't cover everything from the request.

I think it's most important to respond quickly in words that customers can easily understand.

I feel it's important that it comes across that they care about solving the problem. If it's communicated that they're making an effort and what steps have been taken some delays and other things can be forgiven

Empathy is the most important thing for customer support.