People of a certain age write checks. People of a much younger certain age, mainly millennials don’t, instead using their mobile phones for most of their financial transactions.
It would be hard to find an elder who cannot write a check, and most aging children still write them, albeit far less frequently. Some parents have given a check to their millennial young adult, only to have their child carry it around in a wallet for weeks and weeks rather than cashing it.
One reason is that as young people move into their first rental apartments, most of which are properties owned by people rather than corporations, the new renters need to write checks. The owners run businesses that are too small to have a credit card or electronic payment system.