Grumbler, COME is the whole trip. This is about the end of the trip. You wouldn’t have ARRIVED or GOTTEN HERE ON TIME.

Can you elaborate on "whole trip"?
Also, my understanding is that "IN time" means not late, while "ON time" means rather "exactly". Am I wrong?

IN TIME means that you arrive early enough so as to not miss something, and we usually use it with the complement FOR: “Despite the rain and traffic, I arrived (just) in time FOR my daughter’s piano recital.” (= I didn’t miss it). ON TIME means to arrive at an hour previously designated or scheduled and can be used with NO complement: “You’re scheduled to work at 8am tomorrow. You need to call in if it looks like you won’t be arriving on time because of traffic or inclement weather.”

COME as a whole trip includes leaving one place, traveling along a trajectory and arriving at another place. In the context of this post, we’re referring to the final part of the trip - the arrival. In this context we would use “wouldn’t have ARRIVED -or- GOTTEN (T)HERE -or- MADE IT (T)HERE on time. Here’s an example of all these points in one snippet: “I’m so glad I CAME to your surprise birthday party yesterday. We were all supposed to be there by 7 and I had to take a cab, so I didn’t know if I’d be ON TIME. But I had a great driver, so I MADE IT there IN TIME FOR the actual ‘surprise!’ when you walked in.”

OK, thank you

Add other variants yourself if you wish

One more little but important thing - you need a comma in your sentence 😉

✅