While I agree with what you wrote in terms of some of the history (which I have omitted), I think you are eliding the second part of the design equation- the importance of the saving throws.
I suppose we could go into that. As I said, in the classic game, even as effects became more fearsome, saves became easier. At 1st level, Charm Person was hard to save against. At 7th, Polymorph Other was still pretty hard to save against. At 12th, Stone To Flesh was getting relatively easy to save against. 'Save or Die' didn't kick in until 4th or 5th level spells, at the earliest, IIRC (Phantasmal Killer was a 4th level Save-or-Die but the save was non-standard).
Bottom line, you got better at saving (much better, in a Monty Haul campaign, you could often save on a 2 thanks to plentiful magic-item bonuses, for instance), but the consequences of the failed save got worse - much worse.
In 3.0, save DCs scaled faster than save bonuses and spells still increased in the brutality of their effects at higher level, so the game became the infamous rocket tag.
In 4e, saves in the earlier-edition sense were consolidated into the attack roll mechanic, but at least one save was likely to fall behind the curve at higher level. Consequences in the form of conditions still got more severe as you leveled, but we're talking prone or maybe dazed at low level and stunned or something exotic and exception-based at high level. And, durations were much shorter, often "save" (a completely different, non-scaling 55/45 chance) ends or requiring actions to sustain. So consequences were much reduced across the board.
In 5e, saves are back to getting significantly harder as you level and durations longer than in 4e (instead of actions to sustain you merely refrain from casting another concentration spell; instead of 'fixed 10 DC saves ending,' repeated saves vs the original DC are required, etc). Consequences aren't back to the TSR/3e level - no save-or-die, but are more serious than they were in 4e, and 'save for 1/2' can be on a fairly huge amount of damage.
For a WotC-era save dynamic (saves get worse, net, as you level) to be workable in a gamist sense, the effect of a failed save would have to become /less/ severe at higher level. For instance, if damage didn't scale, at all, on spells, even with slots, but saves did. It really wouldn't make a huge amount of sense for petrification or instant death to be available at low level, but not high, though.
So I think it'd make more sense to change the save dynamic.