I'd like to point out that Skarmory can't be obtained without trading in Gold.
Also:
Firstly, I wouldn't compare Fearow to guys like Noctowl or Xatu. Doduo is a better comparison and Fearow beats him in availability by a fair amount of time present.
Spearow is possibly the heaviest hitter in the earlygame, training really easily in Sprout Tower and being possibly the best Pokemon for gyms 1-5. Later on, STAB Return/Fly/Drill Peck off 90 base attacks works wonders too. A must for High IMO.
Seconding this, while also adding that the level 10 Spearow (whose name is KENYA iirc) you get from the guard on Route 35 is awesome. He's a bit underleveled at first, but he doesn't have your OT number, which means he levels up really fast. And after you catch him up, he continues to level up quickly, evolves at a very respectable lv 20, and in general is a beast throughout the rest of the game. Fly is a really useful HM to have, arguably the most useful since it means you don't have to waste time walking or surfing through routes to get back to places you need to get back to, plus it's a pretty good attack in-game that allows one turn of invincibility+70BP (105BP factoring in STAB). For other attacks, you get STAB Drill Peck and Return which wreck shit.
Then again, if you catch Spearow earlier he does an amazing job of kicking Bugsy's butt, and that Scyther is tough if you don't have Cyndaquil or Geodude (but who doesn't have at least one of those?)
I *guess* upper-mid is okay for him, but I would really argue that high would be a better description-- he's every bit as useful as Mareep or Red Gyara. He tears through Morty and Chuck, gets you through the Team Rocket hideout just fine with all the Glooms running around and his STABS hitting hard (albeit neutrally) on just about everything else, his STABS are pretty decent on Claire, he's great against a bunch of Koga and Bruno's Pokemon + Vileplume, and pretty much tears through Kanto with the exception of Lt Surge and Brock.
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As for Chikorita line, it actually is pretty useful. While it sucks during the 1st two gyms, after that it's way better. It tanks Whitney's Miltank better than any of the other starters since Rollout is NVE and it has access to Reflect early on. After that, it's great in Chuck's gym, in the Lighthouse, against Pryce, can hold its own vs Claire (esp Kingdra which can't really do anything to a Meganium), has utility vs some of Will + Bruno's mons in E4, and great in Kanto vs Surge (tanks him), Sabrina (her Psychic mons can't take physical attacks), and Misty+ Brock for obvious reasons.
Sure Razor Leaf is its only good STAB till you get Giga Drain, but it's a pretty good one-- 55BP with a high crit ratio, and you learn it at level 8! Body Slam at level 31 is also really useful -- an 85BP attack coming off Base 82 attack with a 30% chance of para-hax. If you prefer more power, you can always just use Return instead. It also has amazing recovery in Synthesis, which really adds to its staying power without making you waste valuable items. Those Hyper Potions do add up, believe it or not, and not having to use them is nice because it gives you more money for TMs (and the Move Tutor in Crystal)
A good moveset I use in-game a lot is:
-Body Slam/Return
-Razor Leaf (Giga Drain when you get it)
-Synthesis
-Reflect/Light Screen
Reflect and Light Screen are also great if you want to minimize damage to your team and thus save money on potions and such.