Yeah I also felt that the 2015 team on paper and the way they were playing down the stretch, the Jays had a World Series caliber team. It definitely did feel that way. They had an epic comeback, coming back down 0-2 from the Rangers in the DS. The Royals were a tough matchup and everything was clicking for them. f***, even Alcides Escobar was the ALCS MVP lol. Who knows if they were able to pull out a Game 6 win, what could have happened in Game 7. Even in that Game 6, a lot of calls went more the Royals way. Kinda felt like MLB was pushing for KC, but who knows.
Even the 2016 season, despite them winning a WC, you had that feeling that squad could have went on a deep run and they did. Beat the Orioles in a one-game WC at the Rogers Centre, demolished the Rangers, though again ran into a Cleveland team playing great baseball and that had great pitching in the ALCS. Nightmares of Andrew Miller haha. Disappointing series, because Cleveland really walked all over the Jays.
I never felt good about the Jays team in 2022 and 2023 heading into the Postseason. It was more "what if" scenarios and if they got hot at the right time, they could go on a run. The lineup struggled over 162 games in 2023, yet if the bats woke up all of a sudden in Game 163 and 164, the Jays had a chance. Didn't feel that confident with this group heading into the Postseason at all.
Like you said, ironically the 2021 team felt like the best team Atkins assembled on paper and the way they were playing in the final half of the season, but they missed the Postseason. Atkins could have used that "big push" mentality in 2021.