I didn't say they weren't useful. I said they weren't universally very useful, which was your claim.
Sure, it's better to have a higher initiative modifier than a lower one. That doesn't mean that it's better to have a higher initiative than it is to have a higher INT-based spell attack roll.
I played a dwarf battlemaster for four levels, ending in an untimely death at the horns of a minotaur. DEX was my dump stat, because I was leaning in to the archetype. I fired a crossbow a several times over those four levels, and I hit a few times. Mostly I fought melee or used thrown weapons. Frankly, I didn't want to take the time to unequip my shield. I never, ever fell into a pit. DEX would not have helped my AC. I had enough hit points to survive any failed reflex saves -- though I can't remember any particular instances in which I failed the save. Low initiative was not a big deal.
I DMed for a high DEX wizard running from level 1 to 11. She succeeded in most of her DEX saves, and she still managed to be knocked out of the fight by area of effect spells that did enough damage, even on a save, to drop her. Several times. Nearly every time that I called for a DEX save. That saving throw modifier just wasn't much benefit to her.
Well, I have said (at least twice, in this thread, in conversation with you, I believe) that it's often more advantageous to have moderately high scores in multiple abilities than to have one high and one low.
In threads like this, it's easy to lose the context of the conversation. I admit I might have lost that context. But, for clarity, here's the context in which I'm making my comments:
* We're talking about the relative value of racial ASIs in different ability scores and how floating ASIs in TCoE might affect balance. So, when I say that DEX is not objectively better than INT (or any other stat), I mean, specifically, that a racial DEX ASI is not inherently better than one in INT. It depends on character and the way that character is played. I also mean that it is not universally the case that it's better to have a higher DEX than INT.
* You made a list of the ways in which DEX was better than INT, and you stated that none of the advantages that you enumerated were small factors. I said, and I maintain, that for some characters, some of those advantages are small, and some of them are non-factors all together. You simply over-stated your case.