Tetra...I largely agree with the substance of your points, yet as you know about 5e, one can add all of those features back in if you want.
The monster stats in 5e, to me are base templates, that I customize.
I’ve had wraiths with Incorporeal Touch in 5e, Con Damage abilities etc.
The nice thing, from my perspective as a DM, now, I have complete control over the effects, which allows for “A balanced Adventuring day”.
3e had loads of “micro- transactions” required. The fully charged Wand of Lesser Restoration, wasn’t so much a ‘reward’, and more the necessary cost to keep the game moving at a reasonable clip.
Flat Footed AC, Touch AC, Armor AC....all very different...the 3e Wraith would terrify the Cleric and Paladin, Armor AC characters, Touch AC characters not so much, and the consequence was buffing became mandatory as failure to do so resulted in ability damage that could take one or more weeks to recover from, without magic.
I’m not criticizing 3e, base 5e monsters are bland, but I don’t miss having to give out Wands of Restoration to maintain any degree of story flow or flexibility.
That gaming room full off ‘Type A personalities’, the super goal oriented group of D&D players, that are my friends despised that bad rolls in 3e while being under resourced, meant delays, massive hang waving of rules, or evil won.
Try defeating Kyuss or Dragotha with a 5 Constitution score. Not fun for either the player nor the DM.