The advantage of the H-series of codecs is strong support of hardware implementation. This has been a selling point since H.262. You can get a H.265 IP core fro

The advantage of the H-series of codecs is strong support of hardware implementation. This has been a selling point since H.262. You can get a H.265 IP core from Xilinx, Intel, and other major vendors -- so the actual runtime performance for H.266 (once a core is available) will be very low and constant (and comparable to current codecs). Bandwidth and storage space are real costs, despite the handwaving around it, and reducing these requirements while not reducing visual quality is an important step. As for "information-dense scenes": Pathologic cases such as the HBO intro screen are encoded into modern codecs as noise, and regenerated client-side, because there's no actual information there. These scenes are either engineered or pure noise.