The increased collaboration angle is most likely bs.
According to this study open offices do reduce face to face communications: http://rstb.royalsocietypublishing.org/content/373/1753/2017...
The only two rational factors why anyone would choose open office:
1. the floor space really is so expensive you can waste xx% of capital output of labour.
2. You inherit a dysfunctional organization or just a one you cannot trust, and want to "keep an eye" on everyone so they behave. Michael Bloomberg gave this rationale in New York.
3. Bonus round for hotdesking : You expect/have a fairly high churn rate. Why bother assigning people personal spaces since it's so much work to keep track of the facilities. Let the people find their own space. Besides, you might outsource xx% of your operations in near future so it's not like you plan on investing in long term team building.
So, any linear combination 1,2 or 3 should suffice as an explanation. Any serious publication which praises open offices is likely a piece by a consultant who makes a living out of peddling said solutions and are offering political propaganda to make the employees less resistant.
The most common irrational reason: You don't really have an opinion what consitutes a good working space but open offices seem to be trendy ("It's what the big boys are doing") and a consultant made you an offer to redesign your office space, so, why not.