Decent article
"It's important to note, though, that the Snapdragon 765G is likely a far more efficient chipset."
This should not be understated; benchmarks are usually conducted in air-conditioned rooms but in the real world the 845 is likely to throttle slightly at room a temperature, badly if the phone chassis is not well designed for heavy workloads. Meanwhile the 7nm lithography and general architectural evolutions would likely see 765G practically never throttling unless used in hot climates.
Aside from this, newer SoC may carry higher bandwidth connections, and crucially newer accelerators for "AI" and for images, which are increasingly relevant and better suited to their tasks. (Hexagon "685" vs "696")
Regardless, personally I would always take the new chipset for connectivity reasons... Due to server-side processing potentially taking significant portions of compute work - 5G can essentially be considered a contributing factor to a phone's performance now and more in the future.