On async channels it is recommended to get to the point quickly. Sure send pleasantries, but no need to wait until they are answered. You can immediately also get to your point. Instead of sending "hello" and then waiting you would be sending "Hello. I hope you are having a good day. It seems that the turbo encabulator is complaining a vapour lock in the secondary log file. Have you seen that before?"
The https://nohello.net/en/ site describes this communication style better.
If you use chat like it's a conversation then you'll have a bad time.
If you use it like it's business communication like short-form email it's better.
It's bizarre that the same people who will send an email that says "Hey, send me this information asap" will start a text chat with "hey how's it going"
People who say hello and then wait for a reply will wait a long, long time for a reply from me.
If a chat conversation isn't getting a point across after a couple of back and forths (five minutes is too long,) then it's time for a phone call. Discussions in chat are fine. Flat out lack of understanding is best fixed when they can hear and interrupt for clarification.
If I do need to call someone, I simply message them and ask if they're available for a call. There's no need for preamble.
You wouldn't send a letter with just the salutation, you'd include the message! Why treat a Slack message like it's a phone call instead of like a (short, rapidly delivered) letter?
I'm also huge proponent of https://nohello.net/en/ in the workplace and elsewhere.