DND_Reborn, thanks for chiming in with your experience. As I said, I had to go off what I've seen, and that was concentration buffs really compete with other spells casters want to use. That some groups use more buffs on other party members than the ones I've seen helps me to see it's not a universal problem.
ECMO3, that kind of reinforces my point. You can totally play a Cleric who functions that way, and at least until Extra Attack is available, perform as well as a Fighter without much fuss. Since everyone has the same attack chance now, the only thing that differentiates classes that can "fight good" comes down to defenses and # of attacks.
Micah_Sweet, the issue with making Fighters superhuman is that is not what many people seem to want! When you create options that allow for it, you get very vocal complaints that "the Fighter is not superhuman. He can be superhuman in your games, but not in mine!".
The reason why damage cantrips exists is because some feel that "wizard attacking with magic" is cooler than "wizard attacking with crossbow". Until higher levels, there isn't much difference. The fact that damage cantrips scale, on the other hand, isn't too problematic by itself, since it means that the wizard can always contribute meaningfully...but it does became pretty evident when you look at the Cleric that something is wrong.
The Cleric doesn't have good attack cantrips. If they have no attack spells, they are meant to use weapons. But without extra attacks, the only benefit they get comes from their level 8 Class Feature.
Speaking of the Cleric, it's not written that they use their spells to make other players stronger, but if you look at their spell list, the intent is clear. Also, consider this. Using a 3e example-
What is better? Using your action to cast Bull's Strength on the Fighter, who can use it's benefit to attack on his turn (and may get more attacks than you) or using your action to cast it on yourself, when you won't be able to claim the benefit until your next turn?
And yet, most "Clericzilla" discussions usually center around the Cleric using their spell slots thusly. When asked how they do this in combat, the answer is "well they pre-buff", or use non-core elements to cheat action economy or spell durations.
I've played versions of D&D for decades, and rarely do I see groups even have an opportunity to pre-buff. It's usually "hey here's monsters". People will say "well this spell lasts for 20 minutes, surely it will last two combats"- but when is that a given? You have no idea how long it will take to run into another encounter, let alone one where the spell's benefit is necessary.
You could turn the corner and find two Hobgoblins, 20, or nothing but another trap lined hallway (darned Kobolds).