First, if you're a simplistic "Kelly can never get us there" or "Kelly sucks" or "Kelly always fails on the big stage" guy, this post isn't for you. I'm hoping to have an accurate discussion about what's going on.
Had Notre Dame hired a new coach prior to 2017 and this coach had the exact same results as Kelly has the past two years, most everyone here would say that things are vastly improved and looking up. But the thing is, Notre Dame did basically get a new coach prior to 2017. Anyone who doesn't see that Kelly 2.0 is very different from Kelly 1.0 simply isn't being honest. I realize Notre Dame is about national championships, I get that, but in the current climate of the superteams, Alabama and Clemson, championships are difficult to come by for everyone else. The overall culture and ability of the Irish program are still improving, and the team could break through at any time. Making the playoff field is a big deal, and in year two of the coaching reboot, this was accomplished.
As for the Clemson game specifically, the absence of Julian Love in the 2nd quarter was much larger than you might think. Take a look at this: Score for three quarters with Love in the game - Clemson 10, ND 3. Score for one quarter without Love - Clemson 20, ND 0. But more telling is Trevor Lawrence's stats. Without Love, 15 for 18, 247 yards, 3 TDs. Without Love, 12 for 19 for 80 yards. Ifs and buts, I know, but had Love stayed healthy, there is no way the score would have even been close to 30-3. Not saying the Irish would have won, but the dynamics of the entire game are different if Love stayed in, because while he was in, both teams looked very evenly matched.
Also, ND's glaring weakness, the O-line, was greatly exposed in this game. People want to blame Book, but when your O-line is that bad, no offense, no matter who is at QB, can do much. Hopefully this weakness somehow becomes a strength in 2019. And every bounce seemed to go against ND, which didn't help.
So no, Notre Dame isn't that far off. But improvement still needs to be made, obviously.