Layout affects the rent, how many people fit into the space and how the team works day to day. The choice is about the nature of the work, not fashion.
Open space
An open plan fits more people into the same area and costs less per workplace. It suits teams with constant horizontal communication — but noise means meeting rooms and call zones are essential.
Private offices
Rooms give privacy and quiet, important for legal, finance, management and confidential work. The trade-off is a higher cost per employee and less flexibility.
A mixed format
Usually the optimum: an open area for the core team plus several rooms and meeting spaces. When viewing, check whether the layout can be changed.