The ADA is not an outcome (as in success) focused law though? It is a opportunity based law. There is nothing in the ADA saying that everyone with a disability needs to succeed to the same level as someone without that disability, rather that a reasonable accomodation must be made to give them the tools to TRY.
And for the rest, you lost context a bit - I was replying to the comment in the parent post to mine, which asked
'What is your basis for equality of outcome being a bad thing? Can you give some examples of what you're talking about?'
My point is that fundamentally, true equality of outcome (if taken to mean 'everyone gets the same rewards/has the same success') may naively sound nice, even very fair, but is not only impossible, but undesirable when you look at what it would take to try to get there (depending on the degree of course). And when people try to quantify what they mean by 'rewards' it also tends to be obvious that most people's concrete ideas (and scale) of rewards do not line up with each other.
And then gave some examples.
A rephrasing of the idea, is the saying "From each according to his ability, to each according to his needs" (Karl Marx), but there are a great many ways to put it.
There are many non-murderey areas that tend to be eas(ier) to balance, like education. If I've always wanted to be a mathematician, but have no knack for it, does that mean I get infinite tutoring? Most people would say no, and I can't think of anyone that has tried in practice. Many will say 'well, you can get x years of normal education, but if you fail out that's it'. Most will say 'well, you can apply, and if you have good grades, the state can cover it', etc.
Most of those fall on the spectrum of equality of opportunity (aka ability to try/take a swing). Equality of outcomes is when you say 'Everyone should be able to be a mathematician, so everyone (or x percent of everyone) must be a mathematician'. That... gets weirder. What if they don't WANT to be mathematicians? Do we make them? What if their background/interests don't line up, so they hate the studying, and keep failing the tests? Do we fake the numbers? Beat them until they comply? Fail a bunch of everyone else until the numbers match?
This is in no way to downplay very real issues with culture, racism, sexism, etc. that do happen. It's to point out the dangers of taking naive and course metric driven approaches to the problem.
When we're talking wealth, access to jobs and political leadership positions, etc. there is also a long history of it getting much, much uglier.
The particularly murdery/authoritarian examples happen because since it is fundamentally impossible for everyone to actually get the same rewards/outcomes in almost all cases and people can't all agree on what it would concretely mean to even get the same rewards/outcomes, the people in power either give up without succeeding and then get replaced (or rarely, has a coherent enough and smart enough power base that they can give a nuanced and sane answer that is not merely propaganda - looks like Sweden might have pulled that off?), or try harder. In government, try harder often means overpower resistance, purge dissenters, neutralize political opponents who don't support you - to various degrees of brutality. You see it everywhere, in the US, England, Russia, etc. In a revolution, that also usually means lining people up against a wall.
Especially if the power base/population is angry and unhappy, and particularly if it is large (since that typically means the spoils are large for the winners), and since the naive answers sound good, there is huge incentive for someone to also tell people what they want to hear while trying harder, even if they know it's bullshit, and use tools like propaganda, secret police, you name it. It also provides really effective cover to do nasty things in the name of doing the right thing.
There are some really recent historical examples of people getting all the power to try the hardest. Which tends to attract/filter for authoritarian types - probably especially the murdery ones after awhile. See Lenin vs Stalin (or really Stalin vs everyone else who could conceivably challenge his power)
Mao did multiple purges. The Khmer Rouge was.... particularly nasty. All of that was done in the name of helping the everyman and producing a just outcome for the everyday person.