I've mentioned this in prior posts, but it deserves periodic attention.
In most school districts special ed students are "mainstreamed" for several classes. #1, for example, takes Algebra - though he reads and writes at a 3rd-4th grade level . (#2 is also "special ed", but his needs are different. He takes advanced coursework.)
Curiously, and this is why mainstreaming works better than one might imagine, #1enjoys his algebra and seems to get some of concepts, particularly those with visual analogues. (DragonBox helped). He'll never use Algebra in later life, but then neither will most of his neurotypical peers.
Of course he can't follow the regular class materials. That's where the hard job and no pay part comes in. He has an "aide" who is supposed to reinterpret the class material in ways #1 can understand. Yeah, in realtime, without an adapted text. It's a challenging task for a talented thinker who knows the source material very well and can adjust it to the peculiar features of an atypical mind.
That talented thinker is, of course, not working for minimum wage. Instead the most challenging job in education goes to someone with limited education, no training, minimum wage and limited benefits.
It's interesting to think how we might do better even as our funding shrinks.
 Incidentally, long ago, when I was an ignorant physician caring for kids with disabilities, I did not understand how valuable it was to be able to "read at a 4th grade level". That level enables useful email, comprehensible texts, scanning newspapers, reading sports news and much more. The jump from 0 to 4 is bigger than 4 to PhD.