Quoting: Canucks123
does resigning players not exist in the cap-friendly universe?
https://www.nhl.com/news/mark-stone-traded-to-golden-knights-by-ottawa-senators/c-305208914
https://www.nhl.com/goldenknights/news/golden-knights-acquire-max-pacioretty-from-the-montreal-canadiens/c-300023356
https://www.nhl.com/panthers/news/florida-panthers-acquire-forward-claude-giroux-from-philadelphia-flyers/c-332024042
Here are some fairly recent examples of comparable big name players on expiring contracts being traded, and their returns. Note both Mark Stone and Max Pacioretty signed extensions when they were obtained, and each were more proven (Miller is coming off a career year, and we don’t know if that’s who he is or just an outlier season) was obtained (look at that stone deal) for less than you’re asking for Miller.
https://www.nhl.com/goldenknights/news/vegas-golden-knights-acquire-forward-jack-eichel-from-the-buffalo-sabres/c-327563858
And here’s the Jack Eichel trade, because somehow 29-year-old JT Miller on an expiring contract coming off a career year is netting a similar return to Jack Eichel, according to Canucks fans.