how did they even loose all those players?

This is not a Jackets original draft team. Just a lot of ex Jackets that are on active playoff teams.

A couple were just playoff rentals. They lost a few because the Vegas expansion draft and the side deals. Then the sell off the past couple years.
Also, they never really gave Marchessault a chance when they had him and I during one of the GM switches the new GM traded him.

Sorry - I forgot to quote on my first reply...
This is not a Jackets original draft team. Just a lot of ex Jackets that are on active playoff teams.

A couple were just playoff rentals. They lost a few because the Vegas expansion draft and the side deals. Then the sell off the past couple years.
Also, they never really gave Marchessault a chance when they had him and during one of the GM switches the new GM traded him.

Panarin and Bob wanted to test free agency and I think they had specific cities in mind.
Bjorkstrand traded below market value after they signed Gaudreau and had to shed cap.
PLD quit on the team and got traded for Laine and Roslovic.
Domi was the return for Josh Anderson and showed some skill but also some bone head plays. Traded for scraps as part of the sell off.
Foligno got a 1st and a 4th I think (sorry Leafs fans).
Karlson - Vegas expansion and side deal to protect Korpisalo and Josh Anderson I think.
Duclair never meshed with Torts and was traded for Dzingel the year they went "all-in".
Hated that trade - Jarmo got fleeced on that one.
Nyquist ,Gavikov and Korpi - all UFA traded at this years deadline.
Return value TBD.

Very nice explanation. I was going to mention Jones, Johanson and Duchene but then I realized it was players in the playoffs now.