Playoffs makes a team "good" .. that's if they legitimately get in, consistently get in, and win once or twice when they're in. It certainly doesn't make them "elite." As a matter of fact, the way a team accesses the playoffs, i.e., whether they have done the heavy lifting themselves to have won their division also has a bearing on assessing how good a team is, as a "good" team doesn't depend on other teams to lose (one way or another) to make the post season. Backing In thanks to the failures of other teams, IMO creates "demerits" offsetting just how good a team is.
A very good team can make it to the Conference Title game and win it occasionally, thereby accessing the SB. A very good team is almost automatically one who is a Conference Champ who makes it to the SB at least 3X in maybe 12 years (once every 4 years).. but of course as the makeups of teams changes, maybe that's too a period to be a litmus test.
A truly and legitimately "Elite" team fulfills all of the above and actually will become the Champion of The World at least once, but preferably more than that, like The Giants, NE, and Pittsburgh.
Any more flexible, more forgiving self-defined interpretation of "Elite' is just conveniently what they call in my business "Form Fitting" manipulation of results to conform to the desired outcome.
