Aside from having an IEP, I really don't think there was any difference in Gifted and General education. I wish that it truly enriched children. But, we're not a society that values education even at the general level, let alone the exceptional.
Your post was so sad to read.

There are schools out there that value education. You just have to hunt them down. Believe me we did hunt for the right fit for my dd.
The majority of the "gifted kids" in my dd's 7th grade are taking a "honors algebra". 8th grade they take "honors geometry". Upon entering high school they walk into a weighted honors algebra 2. (Although they have even higher rubrics for kids that have surpassed that. You could be walking into Alg 3/Trig or Pre-calc in 9th grade.)
My 7th grade dd is in their "challenge program" and she is taking "challenge pre-algebra". She will take challenge algebra 8th grade and if she makes it thru that OK (has to maintain "B" average), she can take Honors Geometry in 9th.
Regular students are taking Pre-Algebra in 8th grade and will take Algebra 1 in 9th grade.
As far as the other classes the "challenge program" she is in gives her the ability to track to other honors classes for high school.
Now this is HUGE, because most school districts in the area reserve that for only the "gifted kids". And there is where I agree with you. A HUGE majority of kids are left behind there. Many, many kids are above average and can do or WANT to do the higher level classes are are NOT allowed to.
Now this school district will allow a student to take an honors class with teacher recommendations, grades, etc..with a waiver. They make it so a kid could go for it and try. That is why I picked this school. They value educating the students via how they have their requirements set up.
I hope the OP reads this. I love reading that other schools are doing "levels". That is how it should be.