Is Karlsson actually worth this

Yes, Karlsson is producing this year. He is however still a mess in his own end, as is Barrie. He's also 32 with an ankle that's on borrowed time. As he ages, his value will decrease.

This trade gives SJ a poor man's Karlsson who they can keep under a very reasonable contract, or trade for assets, along with a potential top-6 winger if he ever figures out the mental side. The 1st round pick is for the cap retention, however taking on 4 years of Karlsson means that EDM doesn't trade a 2023 1st round pick, as this year's draft is deeper than next year's.

Realizing the mistake they made with their choice in the summer...

Bjugstad has his career back on track, and if you've seen Ryan play this year, the size difference here does matter, as does the age difference.