As for the 18/18 vs 18/3 fighter argument, people are using the corner case of high level dnd, when they really shouldn't.
Sure at the highlest level, the Dex bonus might not matter, but for a good portion of the game it does.
So an 18/18 fighter gets hit less often than than an 18/3, he strikes first, and he has the same offensive. In short....he's a better fighter.
My argument does not consider low level, but that was done for simplicity's sake. At low levels, the curve of how attacks and defenses relate is changing every level, complicating the comparison quite a bit.
Defenses are largely static, while attack scales with every level (for warrior classes).
At level 1, the +1 from level is dwarfed rather severely by an 18 from Str (+4). 1:4. This first level fighter gains only 1/5th of his attack bonus from skill (if that).
By 4th level, the ratio of level bonus to Str is 1:1.
By 16th level, the ratio has flipped to roughly 4:1. So on and so forth...
Admittedly, in the above I'm disregarding feats, ability score increases, buffing spells, magic items, and other possible factors. Nonetheless, I think the point stands.
While I'm no slouch at math, I'm not a mathematician. Systems with three or more variables quickly move beyond the realm of practicality for me. Unlike Janx, I'm not very familiar with excel, so I'm stuck running the numbers in my head or on paper. Hence, I removed as many extraneous factors as I could, to keep the math manageable.
In any case, I don't agree that it's a corner case as you claim. It's not like what I'm saying only applies at level 20, or only at epic levels. We're talking about something like the latter half of the game.
Dexter is a much better fighter than Limpy at 1st level, I agree. However, every time they gain a level that gap narrows (until accuracy becomes 100% for both), and then it's no longer relevant because both fighters can hit each other on a natural 2. I think that ability scores should matter the same whether you're playing heroic newbs, or Hercules and Achilles.
On the other hand, the 1:5 odds of Limpy getting the draw on Dexter are a constant, regardless of level. Yeah, I
still don't like the idea of Limpy being able to gun down Dexter almost 20% of the time in a quick draw contest. Initiative isn't some obscure subsystem that practically no one ever uses. It's a major part of the game and I don't think it should be so easy to make it produce results that I can only describe as wonky.
I don't agree with the thinking that just because an improvement might be difficult to develop, or that a change might come with it's own imperfections, designers shouldn't even bother to try to improve areas where the system is clunky. If that is true, we might as well accept the status quo and play existing editions until the end of eternity. Which is perfectly fine; I would rather, however, hold out hope for something "better".