... why are you responding to a thread discussing His ascension/leaving? What do you hope to accomplish?
It provides a valid option.
There is no verifiable answer to the OP question. Some people tried to answer it, but all they could present is their own opinion. These opinions can be more or less reasonable.
For example, Albion's first post gave what he clearly stated was his opinion... and I don't think it is reasonable. Staying around would not have "diminshed" Jesus' message.
Other opinions might be more reasonble. The old and often used: "He wanted us to have faith." is, in my opinion, not a
good explanation, but it is a reasonable one.
And of course, the opinion of "Jesus 'left', because that is what humans do when they die on a cross" is both good and reasonable. You might not agree with this opinion though.
All just opinions. That is basically the reason why I didn't participate in this thread earlier... I already knew what would come from it from the start: nothing.
In an earlier post you wrote about the (friendly) atmosphere on this Forum when you joined 12 years ago. Well, I joined 14 years ago, and have been active since then. I have also seen - next to the friendliness - that hate, viciousness and hostility that Christians can show towards unbelievers, people who question them, or other Christians who hold to slightly different beliefs.
My facit from all that: Christians in general are not in any way different from non-Christians. The love they show is not different from the love that non-Christians can show... and that is true for the hate also.
Christians are just humans. They are not filled by any Spirit, they are not guided by any God, they don't have access to any kind of divine wisdom.
If Jesus had stuck around, that might have been different. But as he didn't, we are stuck with people who proclaim to speak for him... and common church goers who proclaim their opinions "from the Bible" are not that much different from people who call themselves "prophets" or "messiahs" in that regard.