The great majority of the best players on your NFL football team, unless they are expensive free agents, will come from your high draft picks. The Packers are no exception. Aaron Rodgers came in the first round. So did Kenny Clark, Jaire Alexander and Rashan Gary. Davante Adams and Elgton Jenkins came in the second round.
Every team will hit big occasionally in the later rounds, a David Bakhtiari in the 4th, an Aaron Jones in the 5th, even a Robert Tonyan as an undrafted free agent. But by and large, everything from round four on down yields depth, hopefully quality depth.