James Gasik
We don't talk about Pun-Pun
That having been said, if you gain a Fighting Style, weapon, or armor from a Feat, it's probably already an upgrade to whatever your class is already doing, where getting a Cantrip from a race or Feat is not necessarily an upgrade, since it's something other classes are already doing (there are a few exceptions, like Spell Sniper).You can get fighting styles as an entry level feat, I believe weapon or armor proficiencies are too. You can not get extra attack or some other fifth level clsss feature as any level feat. The need to upgrade or a wand/start/etc for extra cantrips dice or a different cantrip as a character advances is no different from doing the same with melee or ranged weapons. That's the reason why I'm chose other and explained it in post 5... As a thing that would very much be an improvement for the health of the game.
Like, if I'm a Rogue and I get a Heavy Crossbow from a feat, that increases my damage- not by much, but it does. If my Rogue gets Archery Fighting Style, that's again, just a bonus. If my Rogue gets Fire Bolt, it's not doing him more good than anyone else who can use Fire Bolt. And if the Fire Bolt doesn't improve...then it's actively detrimental when he could deal much better damage with an actual ranged weapon already.
As for making casters acquire better implements to upgrade their Cantrips, this would assume that such things exist and could be acquired in all games, and that you'd get them at each new Tier, which is not an assumption 5e makes for anyone (you don't automatically get a +1 sword at level 5, for example).
Unless these implements are nonmagical, but I'm not sure what they would cost, since it's not like a Fighter has to trade out their starting weapon for a better nonmagical weapon to use their Extra Attack.