It depends on your team, the player traits, and coach traits. If the coach has good re-sign influences, yes it becomes easier, to the point of being able to retain a ridiculous amount of talent. Starting with Dallas at like 3m cap room, I had to let guys go.
Morris Claiborne (wound up being best FA, caused me a big hole at CB)
Byron Jones (traded in contract year)
Demarcus Lawrence (traded in contract year)
Brandon Carr (traded in contract year)
It was until I traded Romo to the Bears that I had 15m in room. Until then, I was hovering at 3-5m TOPS. I was about to trade away Travis Frederick because he wouldn't sign under cap. Then I added the re-sign influence for that position for Jason Garrett, and he signed.
Now I sit around 15-20m in cap room all the time, and have all my stars (Dak, Zeke, Dez, Byron Jones, Jaylon Smith, Sean Lee, etc).