Internet is Beautiful

If you need a few minutes or a one on one then that is the question and it's perfectly fine to ask for it. "Hey, I need help with X, can you assist me? when would it be a good time to call each other for a couple of minutes or have a long real time chat?" There, now the person has the power to say no, thus it is not imposing on their time anymore and you have used the strength of text chat to it's full extend.

Hello does not imply any of that, quite the opposite, hello incites anxiety and ambiguity on most people precisely because you don't know if this will be a short fired one off question, a friendly salutation, or a long technical problem solving convo.

For what is worth, I'm neurotypical and absolutely hate massive group chats. Can't tolerate stream chats, despise discord with a passion, avoid slack and team's group chat like the plague. Most of my coworkers think the same, we call all of those the productivity theater. They exist to massage management egos into thinking they are providing value to a team by performing public assistance scenes to project a productivity that is not actually happening. Actual productivity occurs when fulfilling solo task or very tight group tasks of two or three people max. But management likes to see the monkeys dance.