> People being illiterate definitely affects interstate commerce. People not being able to count definitely affects interstate commerce.
Fetuses that get aborted might have grown up to be residents of another state who would've bought products there.
Marijuana sold to medical patients in one state may end up in another, reducing alcohol sales.
Socialized medicine programs offered by state governments might lessen the profits of insurance and pharmaceutical firms that are headquartered out of state.
California's labeling laws result in labels that end up on products sold in other states increasing the costs of those products.
State level environmental regulations may impact publicly traded companies and thus the stock market generally, and thereby people in other states. (This one could be used to justify basically anything)
A higher minimum wage in one state may attract workers from out of state.
Educating children about sex might reduce the number of unplanned pregnancies and thus accelerate demographic collapse, harming the economy more generally.
A gay pride parade might result in social media posts shown in other states with ads next to it.
The passage or enforcement of any law might result in news stories in other states on for profit media outlets. Similarly the lack of such a law may result less work for journalists as they can't write about a law that doesn't exist.
What was even the point of the 10th amendment if it was intended to be interpreted as it is today? It seems to do nothing.