Why hold'claim Osgiliath?

[Quempel]

Osgiliath was strategically needed. In both WW's one of the main goals was to destroy bridges so the supplies and access would be cut off.

My main contention is that Denethor should have destroyed the access across the river before Saurons troops arrived. Faramir could have easily defended from that point. But there are so many other issues in both the book and the movie that don't make sense militarily that I don't really question them anymore.

I really hated what was done to Denethor and his two sons in the movies. I never did really like Denethor in either, but the movies made him out to be worse.