Why are corporate websites so terrible?

Question

Design

There is a task to make a website for a group of companies that are engaged in construction and installation work. Each individual company is engaged in its own area, but they want to get a general site.
Creepy corporate sites immediately pop up in my memory, which either from the main page offer to select a button to go to some mini-site in the region, or they mix everything into one pile so that it becomes unclear whether they are doing something specific or offering all services in general in the world ("full range of services").
Are there any best practices or good examples of companies that have been able to overcome this difficulty?
How would you solve this problem?

Answer 1

www.ozon.ru/context/detail/id/4710758 - here is the answer to the question

Answer 2

submit installation work as a service in construction