First, let's dispel the "bad contract" misconception.
Fowler leads the team in time on ice and all Anaheim defensemen in scoring. He's a lifelong Duck and provides leadership and mentoring for the young defensemen (Mintyukov, Zellweger, LaCombe, etc.). As
@ggha777 says, he has a big cap hit but by no means is he considered to be a bad contract or have negative value. Josh Anderson, on the other hand, is a pure cap dump. You can take them both out of this deal.
Next, let's looks at some statistics, to define our terms:
Trevor Zegras, first 180 games: 49 goals, 90 assists = 139 points, -39
Cole Caufield, first 196 games: 73 goals, 66 assists = 139 points, -43
Without making excuses for this injury-riddled season:
Trevor Zegras, 210 games: 55 goals, 98 assists = 153 points, -41
Cole Caufield, 204 games: 80 goals, 68 assists = 148 points, -39
My point is nothing more than that Trevor Zegras is a good player.
Now let's look at what you've offered here: Farrell, an undersized forward with at best middle-6 potential; Ylonen, 18 months older than Zegras, drafted the year before, with half as many games played and 1/5 the number of points, and waiver-wire fodder; and Barron, who has second-pairing potential at best; plus a late first that duplicates the Edmonton pick and a 2025 first that may become a 2026 pick. What amongst that stew can you confidently argue will even be on the Anaheim roster next season? Or ever? And for all of those possibilities, we should give up a 23-year-old who has two 60-point-plus seasons under his belt already and seems to have made a better recovery from his recent surgery than Cole Caufield, whose historical shooting rate of 14.1% has declined to 8.8% this season?