I think for most folks, it’s specifically about damage-dealing cantrips. A wizard can cast Prestidigitation and Mage Hand all day e’rry day for all I care. But handing them an at-will ranged attack that keys off their casting stat, has no ammunition cost, does as much damage as a heavy crossbow, and scales better than a Fighter’s extra attack is a bit silly. I have no problem with the basic idea of casters’ “basic attacks” being magic instead of weapons, but damage cantrips are just better than weapon attacks (even those made by martial characters) in pretty much every way. Toning them down at least a bit seems perfectly reasonable to me.
First, I don't see any issues with cantrips the way they are though I don't see any issue if folks want to look at other options.
However, the main reason I don't see any issue with them is probably because I don't agree with " but damage cantrips are just better than weapon attacks (even those made by martial characters) in pretty much every way."
1) Cantrips don't benefit from magical weapon bonuses to .. to hit and damage. You can get a wand of the war mage for the to hit side of things but most casters won't have an attunement slot for it.
2) Most cantrips do not add the casting stat to damage the way most weapon attacks typically do.
So consider ... a plain long bow attack at level 11 is 2x(d8+5) from any martial character since they all have extra attack by that point. Average damage is 19. Firebolt is 3d10 at this level which is 16.5 damage. Add a +2 magical weapon and the bow goes to 23 average damage. The bowman will also likely benefit from Archery fighting style significantly increasing the chances of actually hitting the target.
That is the lowest base ranged attack for most martial classes. It only scales up from there. A paladin with improved divine smite at 11 and the dueling fighting style with a 20 stat does far more. A rogue with sneak attack does far more. GWM/SS/Xbow Xpert/PAM builds can all do massively more damage than the piddly cantrips. Yes, the primary contribution of most casters is their spell casting but the spells are limited resources, none of the martial abilities mentioned here are in any way limited.
In my experience, when comparing cantrip damage to all the other options ... it just gives the caster something to do so that they feel like they are contributing to the fight and at least doing something when they don't burn a spell slot on a spell that may or may not be effective. The one exception to this is agonizing blast since, because it adds the casting stat to damage on each bolt, it remains competitive damage wise. Of course, SS/GWM builds will far outdamage it but it remains a useful amount of damage compared to any other cantrip damage options for most casters.
By level 17, when firebolt does 4d10 ... it still doesn't (and shouldn't) even keep up with the three weapon attacks from a level 11 fighter.
So, no, I don't think cantrips are just better than weapon attacks, because they aren't (with the possible exception of agonizing blast).
