W'rkncacnter
Hero
for one, it's not the full cantrip. it's just the rider. so you don't get the (scaling, by the way) damage with it, just the weapon damage.Getting a cantrip on top of a melee attack, such at the Warmagic feature of the Eldritch Knight, you consider trivial?
for another...yeah. i'd consider "cantrip, but with some more damage" to be fairly minor.
by who? because all i've seen about it is a bunch of complaining that it's mediocre at best, and that it only gets good at level 18 when you can use any spell. and running some numbers, it's only really worth it with booming blade, which was added pretty late in 5e (tasha's), so i'd consider it kind of an exception here in that eldritch knight most certainly wasn't written with it in mind.I'm sorry, that is generally considered one of their best, and defining, features.
booming blade is an interesting comparison though, because structurally it basically is a mastery - make a weapon attack and get a rider on top. the biggest difference is in scaling - masteries scale by hinging on extra attack, while booming blade scales by bumping up its damage - including on the rider itself.
except masteries really don't scale much at all, except for giving you additional chances to get them off. cleave explicitly negates scaling by only letting you use it once a turn. nick doesn't even get that. sap, slow, topple, and vex, however, are all interesting in that they don't explicitly negate their scaling, but rather just trigger effects that can't stack (in slow's case, arbitrarily, since it just outright states it doesn't even though normally it would). you could, theoretically, spread out your attacks to effect as many targets as possible - and i'm sure there's situations where that could be useful - but usually that's a pretty bad idea, since 5e so heavily encourages focused fire. the exception here is graze, and well...sure, damage on a miss is nice, but you really shouldn't be aiming to miss as much as possible. so really, i don't think eldritch knight is a particularly fair comparison. these are just different things.
writing this out, actually, i think masteries should have been made so that they could stack with themselves to create harsher effects. sure, they can stack with other masteries, but that's only really helpful if you're a high level fighter or you're two weapon fighting. but more importantly, letting masteries stack with themselves would really lean into the fact that martials, by and large, do damage by getting a bunch of attacks. having masteries not play nice with that just feels...well, it feels weird.