Aren't you already pigeonholed into playing the beggars? If you want to play "optimally", at least. It's not even for the splash, but because of how cheap and powerful it is. Range isn't as much of an issue with the Beggar's either, because you can always get a good close/mid range position on the bots. 99% of the maps are constructed that way.
if we're speaking in a vanilla-only enviroment then you're being pidgeonholed into using it the same way you're pidgeonholed into using phlog, not out of a necessity (the missions are offensively easy), but because you want to be done with them as fast as possible
but if you want to get technical the beggar's a beast of a weapon that gives soldier the ability to contend with a pyro or an heavy...
but in a vacuum, there's multiple factors that stop you from reaching that output that can range from team composition or simple skill, the other launchers might not have the same output and/or economy but are way more accessible than the beggar's since they're less autistic
As for your second point, Scout with less movespeed doesn't feel dead to me. Take away all related upgrades and I'll just play him even more as a Pyro - ambushing bots from the sides and back. He still has all of his damage kit and free HP from money pickups.
because this still hinges on the vanilla maps, and those lack the required density and/or pressure to make you think about what you're doing, there's a reason if pacifist scout became a thing in itself
and yes, even in custom/harder maps/missions you will hear about how there's no specific amount of speed/jump upgrades chosen, but that still doesn't warrant killing off his entire mobility upgrades over one weapon that still won't get used since it's grossly outclassed by his big 3
My stance, generally, is that you cannot get rid of metafaggotry no matter how hard you try. Better games and smarter devs than do-nothing Valve have tried and failed. Incentives and modified playstyles to keep it fun are all you can really do, the rest is on the players. I don't consider "all the upgrades available, but it's on this side-grade vs. some other weapon" modified enough. That's the controversial bit, I guess. A lot of recent community MvM missions have that as custom weapons and my eyes glaze over as soon as I see the torrent of miniscule stat autism.
metafaggotry is a necessary evil, you don't give a baseline for players you'll get a sequel to boot camp pubs basically
nevertheless as i mention again the solution to mvm's balance problem is to tweak the salvageable weapons (as an example decrease the liberty's -25% damage into a -10% damage, all of a sudden you've got an unique and legitimate contender for stock) and make the unsalvagable ones more bearable (letting players have the choice of disabling the knockback on the FaN/scorch with an upgrade).
nerfs should be reserved only for extreme cases like the gas passer (no, as i write again scotres and beggars are balanced, it's a matter of the maps/missions not putting any pressure whatsoever) since like in pvp, players should have the freedom of enjoying alternative* playstyles
*not meme, trolldier is unquestionabily useless as an example, bison spamming wouldn't be if the weapon was good
or in less fancy words, i want to enjoy game and have the less used weapons become more usable so there's more stuff to play around with
