Ironically, Beedrill dies to any mid-tier pokemon with a neutral move. It's got the bulk of Alakazam with the HP of Dodrio. Although in this case, you would be pressed to find a pokemon that doesn't learn a move that hits Beedrill supereffectively. Psychic, Rock, Fire, Flying, Poison and Bug moves. That's 6/15 types that hit Beedrill for supereffective damage, and it only resists Fighting and Grass, neither are meaningful resistances.Furthermore, Charizard's Slash is "super effective" against everything except rocks thanks to crits. You need to take math into consideration. "Super effective" does not mean it's the best move to use in any given situation. All of these Poison-types you are speaking of die to just about any mid-top tier Pokemon without being super effective.
It's worth noting that there are only 7 pokemon with lower base attacks whose primary attacking stat is Attack rather than Special, with a lower base Attack stat than Beedrill (and they all get stronger STAB moves, and have generally better stats in other areas). And of those 7 pokemon, 5 are normal type (Clefable, Wigglytuff, Lickitung, Persian and Porygon) meaning they get STAB on Body Slam/Hyper Beam and many of them get status and utility moves. Of what's left, we have Onix (who is also terrible) and Farfetch'd (who excels as a HM slave). Everything else below it is a special attacker (Alakazam, Starmie, Omastar), and the vast majority of pokemon are faster.
As a point of reference, Beedrill's base stats are the 3rd lowest of any fully-evolved pokemon, beating out only Farfetch'd and Ditto, and tying with Butterfree (who has more utility to help you catch pokemon). It's only pro is that you get it close to the beginning and it evolves quickly, but the starters evolve 5 levels later, you get them earlier and have better STAB moves and versatility. You essentially shouldn't be using Beedrill once you have reached Lt Surge.