I look at it this way. The reason things look the same is because duplicaton of effects is kind of silly. Especially on monsters. Why does monster need a special ability if there an ability that already does the same thing?
A huge question this leads to is which you are more concerned about. Waste of paper when reading a book, or wasting the DM's time and energy (and thus everyone else's) when actually playing the game.
If you are using the monster in play and it has "spell like abilities" (or even spells) then as a DM, in order to run that monster rather than merely read about it, unless it's one of the dozen or spells you have actually memorised, then in order to run the monster you don't just need the monster's statblock open but you also need the pages (plural) in the PHB in order to use all the referenced spells. This makes it far slower and more awkward to use at the table, degrading everyone's experience as the DM needs to be continually flicking between rulebooks. You save a very little designer time and a little paper by undermining the experience of the people actively trying to use this stuff - the DM and the players.
If you make things better in play by duplicating the text of the spells being used onto the monster statblock then you are wasting a
lot of paper while making everything seem cookie cutter.
If on the other hand you use the paper you need to use to make the game flow better to actively customise the effects you can add obvious colour like the vampire hypnotising through eye contact and the succubus charming through a kiss even if the outcome is completely mechanically the same. And you can make unique effects meaning your monsters seem more mysterious and magical.
This is a matter of taste, I guess. Are attack cantrips more, or less, boring than a crossbow? Than darts? Than a dagger? But they all ... function ... in the exact same way.
Less boring
And here are two of my problems. First: Why should everything the fighter does be boring? And second why aren't the mages allowed to express their magic through crossbow-equivalent spells?
More importantly, by providing casters with the always-on, always damage cantrips, it effectively nerfed the utility of higher-level spell. I would much rather casters get a smaller number of much more interesting and bigger booms than the same attack cantrips over and over again.
Which means they will be using crossbows most of the time - which is even more boring.
But you still haven't answered
how the cantrips nerfed the utility of higher level spells.
If you go the #BOOMBIGGEN way. You'll have to remove the cantrip (or just the scaling of cantrips), enhance the number of spell per day of full casters and reintroduce the spell damage scaling. Spells could both scale with mage's level and slot expended.
That depends how you are tweaking things.
Let's say that a damage cantrip takes n rounds to cast where n>1 and does a number of damage based on how many rounds. Why does this cantrip need removing? It too replaces the crossbow and because it takes >1 rounds to cast it neither overshadows it nor the crossbow.
