So this isn't based so much on my own game-play experience, but more on my watch of other play-throughs. Some of the Cantrips available to Wizards & Warlocks seem pretty OP....when you consider that they can be used an unlimited number of times (from what I can see, at any rate).
Though I don't think that Cantrips should be as limited as spells, I do wonder if there should be a limit on how many times you can use a single cantrip within a combat encounter? If only to encourage players to change up their cantrip use during combat.

That said, maybe I am completely off base here, & everyone else finds the cantrip system to be fine. Either way, I'd be curious to hear the thoughts of other players .

Cantrips are just and alternative for basic attacks with melee and ranged weapons. They are not more OP than greatsword of heavy crossbow.

The cantrips are far from overpowered. They just need to be changed to match their rulebook counterparts. Remove the ground effects they create (but still allow them to interact with existing ground effects, e.g. ignite oil, freeze water/blood).

Definitely not.
Even with the "buff" Larian gave them with secondary effects (something we could argue helps making them at very least A BIT different to use) they are still barely of any use when you have... well, virtually anything else in your arsenal of spells.

Right now they are, and it's absurd to say otherwise.

For instance Firebolt missing the target, yet still setting them on fire.
Ray of Frost hitting a target, dealing damage, creating an ice surface, and making them immediately fall prone is far too strong.

The fire surface on firebolt is a chance, not a given. And it's still 2-4 more HP at most. With a fairly low chance to hit on top.
I mean, I get that they may be a bit more efficient than the core ruleset suggests (then again it could be argued that "using fire and not setting flammable things on fire" for instance is a ruleset shortcoming more than anything else) but it's a fact that very rarely cantrips are what is saving the day for me.

I mean, cantrips rarely hit (for Gale and Shadowheart at least) and when they do, they don't add any bonuses to damage (for now at least).

The only good cantrips are Mage Hand (for shove attacks on all the creatures that go for high ground) and Guidance (use it if you know you're about to head into a convo or attempt to steal something).

Obviously Eldritch Blast is great, but that's kinda the only thing Warlock has: Hex + Eldritch Blast.

Cantrips are generally solid at very low level.. so they'll seem pretty good in this context.