Jack the Lad
Explorer
I still don't think that's a big deal because the same argument can be made for the entire evocation school. Fireball potentially does WAY more damage than a fighter could do in one round; that's all there is to it. So 4 skeletons attacking someone should be compared to fireball, not fighter DPR. And it isn't even close to as good as fireball when it comes to damage.
It's not really a big deal until you get tons and tons of guys all at once; that is when the action economy thing starts to really unravel, because you're using the equivalent of 4 or 5 spell slots in one bonus action. THAT is crazy - the fact that 4 or 5 spell slots does more damage than a fighter is meaningless. I mean: of course it does.
It's not just using multiple spell slots as a bonus action that's the problem. It's doing so every round for 24 hours.
Let's look at Fireball.
Here's a table showing the damage you can expect to do to a single target, on average, by spending every level 3 or above spell slot on Fireballs - as always, by PC level and enemy defence (in this case Dex save) - and how many rounds it would take you to cast them all and reach that number:

As we can see, at level 16 and against the +5 Dex save Adult Blue Dragon, we can expect to deal a nice, even 300 damage. That's with 11 Fireballs, though, and those will take 11 rounds to cast, and it's probably unrealistic to expect that a combat will last 11 rounds.
If we go back to the skeleton chart, we can see that at level 16 a Necromancer can summon up to 68 skeletons and control up to 94.
Let's be conservative and summon half that many, giving us 34 skeletons. We can do that using our 4th, 5th and 7th level slots, leaving us with 5 spells in total - 3rd, 6th and 8th.
We know that a skeleton deals 3.325 DPR to the dragon, so our 34 skeletons are dealing 113 DPR together.
In 3 rounds of bonus actions, we've already beaten the Fireballing Wizard's entire daily damage output.
And we can cast Fireballs too, alongside our skeletons attacking.
Side point: anything that resists or is immune to non-magical attacks pretty much throws the chart out the window, and fighters zoom WAY ahead with a single +1 magic weapon. Even if you manage to get up to a few dozen skeletons, one stone golem is all it takes to destroy your entire army.
We've been told over and over again throughout the development process that magical weapons are not assumed or required in 5e. While it's true that that doesn't seem to be the case in the final game, resistance only halves the skeletons' damage output, meaning that instead of requiring - in an absolute worst case scenario, at level 20, when the Fighter finally gets his 4th attack - 12 of our potential 146 skeletons to beat his DPR, we need 24.
Which isn't exactly the biggest deal in the world.
Edit:
In all seriousness, your charts are awesome. Thanks for going to all that trouble to do all the analysis! Even if I disagree it will definitely help anyone else reading to know what is going on.
Thank you! I always enjoy doing this kind of number crunching and exploring whether my assumptions are actually based on fact
