WetGeek The video drivers have been mainlined to the kernel since 4.14 so unless you switch to the LTS kernel (which is still 4.9.x), you won't face any issue on that side. You'll still face issues if you want to map a shared folder from the host on the guest machine if the additions aren't installed. It's also required for some other things to work like the shared clipboard, ubs 3.x, some video acceleration, etc.
