Bungie has detailed the added benefits for those who play Destiny 2 on PC.
In addition to 4K resolution support, the PC version will include the ability to play with an uncapped framerate, and feature support for monitors with a 21:9 display.
Destiny 2 on PC will also feature full mouse and keyboard support, complete with custom key mapping and text chat. Additionally, the PC version, which will be available exclusively through Battle.net, will have a detailed settings screen, as well as an adjustable field of view.
Source: IGN PC Articles