Looking at it from a general perspective that has less to do with games themselves; I would say huge parts of the Assassins Creed games due to the accuracy they often have had with depicting historic architecture and such. Heck, they used the games model of the Notre Dame in its reconstruction. EDIT: [So I just looked this up and apparently it’s just a nice story that has stuck. But the actual model was never used.]
From a more game-focused perspective, there are some real gems in there too (especially the Ezio-Series). Tho that quality has sadly not kept.
I agree, however I think the main cause is studios/publishers just deciding where to allocate the time. Devs are just the ones implementing these shitty decisions.