You can, if you can get your players on board with a rules change which is hard to see as anything other than a nerf to all spellcastibg PCs. Often a hard sell, surprisingly.
Sorry you've found that a hard sell, it's been pretty easy IME.
A couple ideas if you want to "soften the blow":
First, use a spell point system instead of spell slots. This way at higher levels a player can choose to cast a 2nd-level spell and two 1st-level spells instead of a 4th-level spell. A straight 1-1 spell point to spell slot ratio works best IME because it is very easy to remember. Your number of spell points equals your cumulative proficiecny bonus at each level: 2, 4, 6, 8, 11, 14, 17, 20, 24, etc. If you use the Bonus Spell Slots feature, it is simply Bonus Spell Points instead. If you reach 11th level and higher, you can only cast one "High Magic" spell of 6th, 7th, 8th, and 9th per long rest. (This puts all casters on par with Warlock's Mystic Arcanum.)
Second, soften the concentration mechanic for spells which allow repeated saves, such as
hold person. If a spell requires concentration but allows a target additional chances to remove the effects of the spell, the target makes additional saves (or whatever) at disadvantage while you maintain concentration. If you lose concentration, the spell continues but the target gains advantage on the saving throw. You can choose to voluntarily drop your concentration.
Finally, employ any or all of the new features below to allow casters more versatility without drastically increasing their power.
Bonus Spell Slots (
most helpful in tier 1)
You have a pool of spell slots equal to your spellcasting ability modifier. When you cast a spell, you expend spell slots from this pool before expending spell slots granted by your spellcasting feature. Your pool of spell slots resets when you finish a long rest.
Cantrip Recharge (5-6) (
if you want to keep combat cantrips)
Whenever you cast a cantrip, you cannot cast an additional cantrip unless you make a successful recharge roll at the start of your next turn. Roll a d6: if the result is 5 or higher, your cantrips recharge and can be used again. Your cantrips also recharge whenever you finish a short or long rest.
Maximal Upcasting (
one of my favorite house-rules, period. it makes upcasting actually worth it at times!)
When you cast a spell using a higher level spell slot, any additional dice gained are considered to automatically roll the maximum possible. For example, a 3rd-level Cure Wounds would not be 3d8 + spellcasting ability modifier, but 1d8 + 16 + spellcasting ability modifier. The two additional d8s are automatically 8s, for an extra 16.
Prepared Spell Exchange (
a useful feature for times when you realize you REALLY needed that certain spell)
Whenever you finish a short rest, you can exchange one spell prepared have for another spell you can prepare. Once you use this feature, you cannot use it again until you finish a long rest.
Spell Recovery (
a powerful feature, but at a fairly high cost---your next action)
When you cast a spell with a casting time of 1 action, you can use an action before the end of your next turn to attempt to recover the expended spell slot. Make a spellcasting ability check with a DC equal to 8 + double the spell slot level of the spell you just cast. You can use this feature a number of times equal to your proficiency bonus and regain all uses when you finish a long rest.
All of these have been used in multiple groups over the last six years or so. Nerfing RAW cantrips, or removing combat cantrips entirely, is small change when you have additional spell slots (or points) available.
i wonder if the people who have issues with cantrips would continue to have issues with them if all of the damaging ones were removed? maybe a few might remain but become class features, like how eldritch blast is for warlock in 5.5(IIRC), vicious mockery for bard, sacred flame for cleric...
but if it was just ones like light, mage hand, mending.
This is also a nice way to go, but depending on how you implement it, if the "cantrip-like" feature can be used every round anyway, it doesn't change much IME.
