I wish I were as confident.
If this were an overall player-for-player skills showcase, I think there's no doubt Tampa Bay is the better overall team and maybe by a comfortable margin. They have so many players in the "very good" category that aren't getting accolades for being elite; it's crazy that they have zero all-pro players and just one pro bowl selection in Pierre-Paul. Pierre-Paul might not even be in the top 10 most worthy pro bowlers on the team. They're really stacked with above average talent almost everywhere, and while their secondary is indeed their weakness, it isn't horrible and has also been the unit most responsible for their previous two playoff wins.
My concern about the game is that Kansas City uses its superstars really, really well and uses them to make their other players better. It's almost muscle memory for Mahomes to hit a wide open Kelce or identify in a second a huge gap for Hill to exploit. Shutting down those connections are incredibly difficult, a lot like Brady/Edelman/Gronkowski. You have to sellout so much to stop those two that other players tend to feast, and the players and coaches all understand their strengths and weaknesses so well.
Defensively, it's kind of the same thing. The KC defense isn't overloaded with "very good" players like the Bucs, but they know how to play within their scheme really well. They have Matheiu and Jones covering up a lot of talent deficiencies. They have a lot of unspectacular players who are well coached and well integrated, whereas Tampa Bay's defense has a lot of highly talented players but still seem to miss assignments, have communication issues, etc. They have cleaned it up quite a bit the last two games, but it wasn't long ago that some no name for WFT was burning them.
I think this game will be very close. I still give KC a very slight edge, but unlike a lot of forecasters, I think if both teams bring their A game, execute well, and don't make critical mistakes, TB has the advantage.