Agents of S.H.I.E.L.D.'s final episode was a strong ending for the long-running ABC series, but it may have also established how little the Marvel Television era of shows mean to the wider Marvel Cinematic Universe. While the show has been doing its own thing since Captain America: The Winter Soldier, the hope was that this final season would tie into Avengers: Endgame somehow.
We did get mentions of the Quantum Realm, alternate timelines, and even time-travel, but even after the team returned to their timeline, there were some big hints that their adventures don't take place in the MCU. For starters, when they arrive in 2020 (two years after the "Blip"), the world seems perfectly normal, and a hopeful place rather than once that's been decimated by Thanos.
Throw in the fact that Mack has donned Nick Fury's trenchcoat to lead a new S.H.I.E.L.D. - who were completely M.I.A. from that final battle with the Mad Titan - and Quake heading into outer space, and it's beginning to look like these adventures always took place in some sort of alternate reality where Fury was able to resurrect Agent Coulson shortly after the events of The Avengers.
That's an intriguing prospect, and one which explains a lot. It's likely something Marvel Studios is planning for all of the Marvel Television-era shows, especially as Kevin Feige had limited involvement in them.
What Culture actually has a full recap of this series finale of Agents of S.H.I.E.L.D., so if you want to know the final fates of each character, be sure to head there to take a look!