First off - comments aren't the proper place for feature requests such as increasing the size of the comment box. For a feature request, please ask a new question.
Secondly, your comments were deleted for being not constructive and for being irrelevant to the post at hand. Let's take a look at what you wrote:
Communities cannot be small and alive. At the moment to me who is not concerned about meta issues and dont even know what they are SE is better. They have a written chat where one can discuss matters calmly not under threat of downvoting or deleting. They have more users so of course more questions and answers. I have already mentioned often how can you be better than SE and bring more users here. Mainly by changing the voting system. But you insist on copying SE.
I also wish the comment box to be a bit bigger to hold 500 letters. Then as you type you can already also see what you already have written. Why must I first have to type it in a word type program and then bring it here. It cant take much developing to increase its size.
The first comment here is not productive. It's complaining about Codidact because your suggestions (such as preventing downvotes unless there were already upvotes on that post) weren't taken and immediately implemented. (You received answers as to why people disagreed with your ideas, but the impression you gave was that people should just listen to what you were saying, without you listening to what people were responding.)
It also wasn't directly relevant to the discussion at hand. The question was about why someone would prefer Codidact over Stack Exchange. That's not the place to raise a complaint about an issue you had with Codidact.
If you honestly believe that Stack is a better option, and Codidact isn't viable in its current state, that's perfectly fine. Participation here is voluntary. The door is open, in both directions. People can come and go as they wish.
However, what's not acceptable is consistently denigrating the efforts of users here. Constructive criticism is perfectly fine; dumping on the project as a whole is not.
The comments were (silently) deleted because they did not add anything productive to the question, were not relevant to the issue at hand, and to prevent the discussion under that post from escalating.