Hell no. Making attendance optional sacrifices way too much.

It's like reducing incarceration rates by never jailing people for anything short of murder. Sure, it improves on that one metric. Obviously. But the adverse effects elsewhere make it a nonstarter.

If you could trust self-selection to only ever stop the "lost causes" from attending? The absolute worst, most disruptive, least likely to ever benefit from education students? Then maybe.

But in practice, for every student like this there would be ten more who would benefit from school education if they attended, but wouldn't attend if it was optional.

And for those missing students, the difference between getting the classes and being left to their own devices might be the difference between becoming functioning adults, low in income but stable, and being locked in a vicious cycle of poverty, substance abuse, violence and crime.

Which is bad for the students in question, and even worse for the society.

But going to jail and getting an education are completely different things...nobody wants to go to jail.