Have been AFK & stuff, hence why I haven't posted much recently.
I can kinda see the case for the movepools thing.
If a Pokemon species stops learning moves at a much lower level than other Pokemon, that implies the yields for its training, or its potential, are lower.
Most evolutionary lines, Pokemon can continue learning moves at level equal to or higher that which they evolve at, but if a Pokemon can't learn more at that point & beyond when most other species, including in their own line can, that suggests lower potential, no?
This doesn't necessarily mean Stone Evolutions should be weaker than others of their evolutionary stages, especially if we assume profiles to be Level 100, but I can see why some would interpret it that way.
The arguments opposing this seem to be that making intepretations from in-game movepools is "headcanon", despite these being an everpresent aspect of the mainline games.
Developer intent can be inferred from the low quantity of moves as well as the low power of these moves in these limited movepools. Though admittedly, some may find inferring from absence shaky, especially given all the rhetoric about proving a negative.
yeah, because they evolve quickly with their evolved forms already having big movepools from the previous game, again, no reason for small movepool to equal weak mon outside of "i think this was the intention" with several other options being available, heck, Pichu is an early catch in Sun and Moon, being threated as the same as the likes of Ratata and the Starter, that alongside Caterpie's trainer battle stuff i said earlier is clear cut evidence that what you are saying about "bad"(in your opinion of course, not an in game statement of it being a "bad movepool") is a non factor for them
On the topic of location/progression-based scaling, the same game has fellow Baby Pokemon Cleffa found on Mount Hokulani, alongside late Level 20s Pokemon & Trial Captain Molayne.
In D/P/Pt & the remakes, it can be found in Mount Coronet at Level 14 &, after the National Dex, as a Special Pokemon at slightly higher levels in The Trophy Garden.
In PL:A, it is exclusive to Mass Outbreaks. Per Bulbapedia:
"All Pokémon found in massive mass outbreaks will be at least level 60, unless the Pokémon's species is one that evolves starting at a specific level, in which case non-alphas of that species will be found 1-3 levels under the level required for evolution."
It can be found in Mass Outbreaks at the Cobalt Coastlands (Unsure what the levels & progression are for that area.), & at Levels 43-46 in the Fabled Spring.
It is available in Max Raid Battle Dens in Sw/Sh.
& it's in Kitakami at Levels 13-18 or 57-62 on Reveler's Road, among other areas, & at the highest in Kitakami, Levels 25-33 or 63-74, with the level ranges depending on if the player has completed The Way Home.
By these metrics, Cleffa seems not quite early game.
Interestingly, 1 possibly contentious avenue to look into may be Max Raid Battles & Tera Raid Battles, which has a Star Ranking system; In both of those, Cleffa is exclusively 1 Star.
Also, I may have misremembered the quote I read about. I looked it up recently, & although I haven't checked all the game, I found this, seemingly from Bug Catcher Benny in Johto:
Trainer 04:{S} Bug POKEMON evolve young. So they get stronger that much faster.
{C} BUG CATCHER BENNY
{E} Just evolving isn't enough!
{A} POKEMON become stronger if they evolve. Really!
Source (Hopefully that's okay to link to.)