Before 2018 IMO Chiefs and Reid never had the right horses for Reid's system, his best players usually were defensive or runners. Even in 2017 Hill was basically a baby. Alex Smith really limited what they could do. While Tennessee was lucky to win, Indy in 2013 had the better offense. Even in Philly where he had McNabb outside of TO and DeShuan Jackson one year each never had the players that fit Reid's strategy. Bowe was pretty much done by the time Reid got there and Gonzalez was gone. Westbrook, Dawkins, Alex Smith, Jaamarl Charles these were the sorts of guys whose talents didn't really fit with Reid's strength. When your best players are running backs and on defense that system isn't utilizing your talent properly.
Every time Reid got to the NFC championship game he lost his opponents were simply better at what he did. Rams had Bruce and Holt, Panthers had Smith and Muhammad, Bucs had Kewashan Johnson and McCardell(and the better defense obv). Cardinals had Fitzgerald and Boldin. At least half those guys are/going to be Hall of Famers and the rest were perennial pro bowlers. Reid was never going to win a shootout with any of those offenses. Remember in 2008 when Eagles were pretty close to winning and the Cardinals did what the Chiefs did this playoffs cause the game Reid wanted to play was one the Cards were better at.
What's really ironic other hand those mid to late 2000s Chiefs would have been a great fit with Reid. So would the Eagles roster Chip Kelly had after Reid left. He was just always in the wrong place at the wrong time before he got Mahomes, Kelce and Hill.