[thinkharderdev]

I don't think it's particularly obvious or necessary. AWS makes its money on big enterprise customers who probably don't want or need this feature. Hobbyists learning AWS in their spare time are a rounding error on AWS revenue.

I would bet that the reason they don't implement it is not that they're being "shady" but because they don't care about the hobbyists and personal projects and implementing hard spending limits would be a huge, complicated feature to implement. And even if they did put in the huge effort to do it, individuals would still manage to not use it and the steady trickle of viral "I accidentally spent X thousands bucks on AWS" stories would continue as usual.