Pidgeot has pissed me off in recent years, because while I love its design, its Mechanically poorly designed.
The Evolution line goes from Base->18->36, which is about on track with a Starter, but despite all of the effort required, its clearly missing a lot of BST. 469 (479 Gen 6 Onward) is really bad compared to most Endgame Mons, it should be around 500-510, TBH.
Pidgey/Spearow seem to be designed with Long Term Power vs Short Term Power as their dynamic, but Pidgeot is like, less than 10% stronger overall, and is much less specialized. Sure, Fearow should remain better Offensively, but Pidgeotto and Pidgeot should have beefier numbers than what they have.
I haven't finished the video, but I really can't stand seeing Arbok so high. A base 60 HP, 85 ATK, 69 DEF, 65 SP. ATK, 79 SP. DEF and 80 SPD Pokémon? This Pokémon's coverage is the 8th Gym Leader's (aka, right before the E4) TM Reward, Earthquake, a one time use Rock Slide Move Tutor inside of Rock Tunnel, and Normal moves. Sludge Bomb is on the freaking Sevii Islands. Glare is literally the same as Stun Spore in this game, and Butterfree even has Counpoundeyes to help with the accuracy! Its best STAB is Acid... Intimidate is not even a guaranteed ability on it... we are literally talking about one of THE WORST Pokémon in FRLG.
Well, even if I'm wrong and you later in the video realize how utter shit Arbok is compared to almost the entire Pokédex, I've done my job boosting the algorithm. I'll finish watching now.
I don't think you give enough attention to base stats.
The difference between Graveller and Golem is more than arcane imo. Gravelled goes a few tiers lower imo.
Edit: seven island is after the elite 4 so you can't bring swords dance kingler to the elite 4 (except for the rematch which I personally count but I don't think you do).
Charizard and Venusaur should be S tier and A tier respectively. Venusaur makes early game super easy and is an amazing pokemon for the E4, Charizard isn't too good until flamethrower, but after that its good. Even though its weak early game, having a fire type on your team that early just makes the later game easier. And it pains me to see arbok that high on the tier.
After watching this video and reading some of your comments, I think your ranking criteria are a little contradictory. Sometimes, you are listing early evolution and good availability as a benefit (for instance in your comment about Arbok), but other times, you don't consider it at all. Dragonite for instance is a pure endgame Pokemon, it literally is unobtainable until after beating the 8th gym if you are using hardcore nuzlocke rules. Dragonair by itself is definitely not A rank material, its stats and movepool are similar to Porygon and Wigglytuff.
I think the ghosts are definitively better than you put them, especially if given the Psychic TM. (Which... honestly, it's a hard sell on Leaf Green, I admit it 100%, but without Starmie or Slowbro there's really not a lot of competition for it in Fire Red)
It absolutely clowns on Koga. Psychic one shots everything he has, even if you have the slowest Haunter in the world you're ok because the only thing his team can do to you is not very effective sludge. Muk will not go down as easily, but you also have Night Shade in case he starts getting trolly with Minimize.
It also is really great against the long stretch of Rocket fights in the midgame, and sure those aren't the hardest fights, but this one pokemon destroys 90% of the grunts on its own. The grunts are almost always packing Fighting, Ground and Normal types (immune) or Poison types (Resistant, plus they don't have strong poison moves). The only issue are the few Drowsee-line users... but you can also feed them Shadow Ball TM? I didn't do that myself, its possible the Ghosts can't one shot and get KO'd back cuz weak to Psychic but yeah.
It's a long stretch of the game where they're extremely good. And they are also guaranteed encounters since you can repel manip to avoid Cubone (which I think is the right play unless you missed out on every other ground type and got your Diglett killed)
I imagine it also performs a similar clowning duty on both Bruno and Agatha, which are the lesser problems in E4 sure, but I think its worth mentioning
(I also wouldn't hold their Sabrina performance against them... Jolteon is a guaranteed encounter and absolutely clowns on her. As does Snorlax I believe.)
I know you don't consider availability very much, but I still think you are way too low on the starters. It feels like you are trying to make the point that they are overrated, but then take it way too far. While Venusaur has very similar uses as Parasect, Vileplume, Victreebell and Venomoth as a sleep user, it has by far the best stats once fully evolved, gets a better STAB in Razor Leaf earlier and has other superior options such as Growth and Synthesis for lategame. Making Misty basically free is also more than what Pokemon like Golduck can do, who are easily replaceable.
Charizard is not great until it learns Flamethrower, but after that, it is very comparable to Arcanine. I would even argue it is better if Arcanine doesn't have Intimidate, because Charizard has actual good coverage moves. It is basically the same as Moltress in the lategame, but has actual uses early. Are you seriously saying that Charizard is worse than Lickitung and Porygon. Both Charizard and Venusaur should be at least 1-2 tiers higher.
While we are on Arcanine, you probably should have mentioned that you really need to buy the Flamethrower TM from the gamecorner to make Arcanine good, which might mean you won't be able to afford Ice Beam for your water time until much later. This problem applies to quite a few Pokemon that need those gamecorner TMs to function at maximium efficacy, including top tiers such as Clefable.