Publishing a paper, writing a grant application or handing in a conference abstract involves co-authors in most of the cases. Comparing publications written in the 1950's with some of today clearly shows that co-authorship has become much more important. While preparing samples or conducting the experiments saved you only a place in the Acknowledgements a few decades ago, today these contributions push you in the author list. In the era of publish or perish is it important to have a lot of publications and as one can only write a limited number by themselves a spot on the co-author list is usually not declined - at least not by early-career researchers. The decision who makes it on the author list and who not has certainly led to some heated debates and broke some collaborations.
But even if you safely make it pass beyond this critical point and you have designed the perfect co-author list, there are some more pitfalls along the way:
Just very few manuscripts are written in one go, read by all the co-authors once, everybody is happy and the whole piece is handed in and gets accepted right away without further modifications. All the other papers go through a more evolutionary process. They are roughly drafted in the beginning, somebody is not happy with the content, the flow or some specific wordings, graphs are added, edited and deleted again and sometimes the story from the beginning is replaced by something totally different. All before a reviewer has even opened the file for the first time. Some main authors try to include all their co-authors along this way, asking for opinions and aim to keep everybody on the same page. But it is a lengthy process, esp. if the authors are distributed over several continents. It can sometimes take weeks (or months) before the last co-author has replied to the latest version and the whole writing process becomes very lengthy.
Some main authors try to cut this time shorter by not including the co-authors so much. This can mean that several iterations are done "in house" before a more polished version is send around again - and that is fine, as everybody has enough on their plate to not be bothered by too much detail. But the other strategy to speed up the manuscript development is to vanish with the manuscript after the first iterations and show up with it again after it is accepted by the journal. Without a notification that it was handed in at all, without sending around the final manuscript for approval, without discussing the changes suggested by the reviewers. This is not acceptable but happens all the time! And besides that having your name on a published document without your consent is surprising, it can if you are really unlucky drag you into the depths of scientific misconduct - and you didn't even have the chance to avoid it.
This "time saving" behavior is not only common to speed up the publishing process, but to be able to hand in a conference abstract a day before the deadline and I guess a few people have found their names on grant applications as well after they were handed in. It is a tricky situation to deal with as usually the main authors are least somehow your collaborators and as an early-career researcher you need publications. So why shoot yourself in the foot by complaining to the main authors (or maybe even to the journal). Most of the time the content of the publication is still fine, even though the general behavior is not acceptable. On the other hand: this kind of behavior is not acceptable! It is disrespectful and patronizing, it shows that your main authors couldn't be bothered less about your opinion but think that maybe for political reasons your name should be on the paper. If possible I try to avoid working with people showing this publishing habit.
Sadly, the "time saving" virus infects grad students as well. It is sometimes very hard to explain to them why having the consent from your co-authors should never be harmed by their poor time management. It should not be too difficult to write the conference abstract quite a bit before the day of the deadline, so that the co-authors on the other continent in a different time zone have sufficient time to reply.
There are certainly difficult situations, e.g. when you have to deal with more than 10 authors. Keeping them all on the same page is a big task. But if you try - and lets assume the author list contains only people with a general interest in the paper and not a bunch of "political authors"- the time put into this "net working" project is well spend and last in better collaborations. Everybody likes it if their opinion is valued.