The average nationwide violation rate for selling tobacco / vape to a minor has been hovering around 10% now for over a decade (9.6% as last reported in 2018).
In fact, since 2011 retailer violation rates have been increasing, and the FDA is stepping up their game.
And because in a number of states violation rates are still upwards of 18%, not only has federal enforcement increased, but strong enforcement is being conducted at state and local levels as well.
To complicate the issue further, in 2020 the FDA raised the legal age to purchase tobacco to 21, increasing the population of buyers that need to be screened and declined. And the burden of prevention of underage use primarily falls on the retailer - you.