To make a meaningful upgrade, it likely would have cost their 2023 1st round pick (that was used on Benson) + more.
Trying to trade futures for immediate veteran help looks like giving up a pick that can turn out great, or an underdeveloped prospect that turns out great in the long run, for immediate help.
One of the biggest win-win prospect for vet trades ever was Calgary trading veteran top 6 C Joe Nieuwendyk to Dallas for Corey Millen and the first player that the Stars drafted after moving to Dallas: Jarome Iginla. Iginla was a Stars prospect for all of 5 months and 11 days before he was traded.
I think both teams were happy with how it worked out. But, Dallas did have to give up a prospect that turned into a HHOF to get a solid vet.