The act of visiting grandma doesn't need to be legible to the economy, rather the time that might possibly be used to visit grandma needs to be illegible to the economy.

Speaking from a US perspective, the straightforward solution to this was defining full time work as 40 hours per week, and then incentivizing companies to not go over this (by automatically increasing pay rates). In addition, the setup where men worked in economically-legible employment while women did not effectively halved this number.

That number was never updated with women entering the workforce, nor with automation, offshoring, etc. Meanwhile the whole idea was undermined with the dynamic of "exempt" salary positions. That limit of 40 hours per week should be something like 15 hours per week in the modern world!

Furthermore, the surplus income from all this extra employment didn't end up going into workers' savings, thus creating a natural market feedback where workers would have more market power and insist on working less (as the marginal utility from the dollars for each hour worked would be less). Rather it went into nearly-zero-sum competition for housing (aka rent), which the article touches on as the forcing function that demands continued high-hour employment.