Probably the same reason you trade Ristolainen.

Sabres were dead last, He was a pending ufa who probably wasn’t going to re-sign

I swear he was an RFA, but I mean, I guess Reinhart was too

Kinda surprised all we got was a 3rd rounder

We got a 1st for risto lol. looking now like the return should have been swapped - 1st for Montour and a 3rd for risto :O

Because they were a garbage team and the locker room quit so they started moving everything out

2 different gms

Had to double check to make sure. He signed a 1 year contract with the Sabres in 2020-21 that walked him straight into ufa. Probably even then they knew he was gone not wanting to extend beyond 1 season

Look back on the post in the trades section, and you'll find some very funny comments in hindsight.

You will also find a comment from me, being correct as usual.

Why not a 1st for both?

Montour was really good for us after we acquired him at TDL. However the following season, he was awful. Hence why we got a 3rd and nothing more. Had he been on his game and playing better, probably could have fetched a 2nd and maybe an AHL-bound prospect.

First, Montour was an RFA, but Florida was able to sign him below his qualifying offer. @coga16 you are correct he was a UFA, my bad!
Second, he did very well the final 20 games of the 2018-2019 playing for Housley, but then sucked because Krueger was his coach and tried to change him.
Brandon along with Miller, Okposo, Sheary and too many others for me to remember had their career worse years playing for Ralph.
Third, many of you will disagree with me, but Adams was the GM and made many really bad moves prior to Jason Karmanos being added to the staff (trading Montour (2021-Apr-10) and Hall (2021-Apr-12) for a 3rd and 2nd respectively, letting Ullmark walk for nothing, signing Eakin over Larsson, trading Marcus Johansson for washed up Eric Staal, not signing Pysyk the first year, need I go on?).
Jason Karmanos (hired Apr 14, 2021 notice the dates of the Hall and Montour trades, Reinhart, Ristolainen and Eichel were all traded after Jason was hired), Jeramiah Crowe (head scout led to better draft picks) and Sam Venture (advanced stats) are the making Kevyn look really good.
Finally, I completely agree, it was an absolute tragedy to let Montour go for only a third.
Getting him for a late first (who is Brayden Tracey) and Brenden Guhle was an absolute steal at the time.
Imagine the Sabres with him and Ullmark right now.
Three top pairing defensemen Dahlin, Power and Montour and a great GK with Ullmark.
That is the back bone to a Stanley Cup team.

I finally explained why I always credit Karmanos in my posts.
OK you can tell me I am wrong now!