Like another poster already mentioned, reminds me of the Harrison Bergeron story by Vonnegut - seems like we are rapidly approaching that point.
x + 3 = 7
Instead, they will get questions such as
__ + 3 = 7
They might not formally learn it, but they'll learn the patterns that they will eventually apply in algebra.
"Solving linear equations with multiple variables", "solving quadratic equations", "solving polynomials", etc. Those are things you really need to teach as a distinct concept. Algebra is just the language, introduced in a pedagogically sound way you wouldn't even realize you were learning it.
Even "new math" is too rote/heavy on memorization of process. And not enough patterns/puzzles/games/etc.
We need to find a way that the math content can be interesting for 80% of the room, and provide competition where there's multiple axes of success and multiple ways to stand out. Then you get everyone in the room really trying.
Instead, what happens is this: we start with curriculum that is very algorithm-heavy, taught by elementary teachers who generally do not love math. Half of the kids struggle with the rote-heavy workload and fall behind, and it becomes a frantic effort to try and drill steps into kids' heads who just hate it more and more. For a lot of the class, this is very painful and zero-sum, and it's only fear of what the teacher will say to parents that generates any effort.
[Note, I do think there is a point around 3rd grade developmentally where it makes sense to drill some arithmetic processes, and around 8th-9th grade to drill some algebraic process... but algebraic ideas can come in well before that time and hopefully be taught in a way that makes them interesting].
Ideally everything would be taught this way, like actually doing interesting things rather than just remembering things from textbooks.
Fast forward a few years in school when the teacher introduced algebra in class (maybe sixth grade?), everything suddenly clicked, and I pretty much got the highest grade for several months straight because I learned this material before, albeit not well, but still way ahead of everyone else.
I think this could be a middle ground: introduce the material earlier, but with no expectation that the pupil must grasp it immediately; then review or reintroduce the material again at a later date.
In my experience, kids whose parents help teach concepts and don't just leave things up to school generally end up with an advantage. Kids love learning from their parents and other loved ones, but school is generally regarded as sort of a chore even if it does bring friends and playtime. A great many parents simply don't have the time or energy left after their day job to support their children the same way others can. Kids whose parents often read to (and with) have a noticeable advantage in many school settings, and you can't substitute that for all students by just cramming in more reading time in their busy school schedules.
Kids have a finite time they spend in school. You can shuffle the time they spend around all you want, but in the end every kid requires a certain amount of time to grasp a certain context. That time may differ when kids get older or younger, but the required time spent on learning won't suddenly change.
Everything builds on other concepts and people's misunderstandings generally came from not truly understanding the basics. Its hard to personalize education at scale though.