Throws dart
*thunk*

Why don't you get Brave Bird? Why? Hell, Sword and Shield finally made it a TR and gave it out like candy, and you didn't even buy a ticket to Galar? Why do you suck so much?
Seriously though, Fearow has to be one of the most depressing birds out there. Like, it's actually baffling how the devs have forced Fearow to use Drill Peck for 20+ years, never giving it any alternative. It does have a design direction though, and that's it basically being "crit bird", with Sniper, Drill Run and Focus Energy all being things in its movepool. It can't even be consistent there though, like, it's so painfully frail and usually won't be able to set it up. As a result, it often just goes halfway and becomes an inconsistent mess. But, this is its only niche, which is the central issue: its niche is something it can't do well at all.
Does this apply to RBY? Not at all, it doesn't even get Focus Energy to be funny in Stadium OU where it actually works(!)
In RBY, Fearow is kind of between Pidgeot and Dodrio in the "Normal/Flying Hierarchy", getting Drill Peck but not Body Slam. Unfortunate. On top of this, it's not really as minmaxed as Dodrio, which puts it in a weird situation of not really doing enough damage while simultaneously taking quite a bit itself. The one thing Fearow has over Dodrio is Mirror Move, which gives it a cool play where you switch it in on Earthquake and get to use it next turn. Is it good? Eh...it's ok, but predictable in a real setting. In RBY NU you usually end up in bird mirrors due to it...speaking of that, Fearow is actually quite good in NU, try it out!
This isn't really a Pokemon that sucks, it's just painfully mediocre and is in desperate need of better STABs in present times. I hope it gets the help it needs if it somehow gets to Galar.