A committee that was set up to determine safe drinking levels published a report that stated the safe drinking level for men was 28 units of alcohol per week (roughly three bottles of wine) and for women it was 21 units (roughly two).
A member of the committee, Richard Smith, the former editor of the British Medical Journal, later said that they couldn't actually find any scientific evidence to justify these limits but thought they ought to publish something as that was what they had been tasked with so they just "plucked the figure out of the air".
Comment: This is how most public health recommendations work, when the justification isn't monetary in nature.
Some time later, the safe drinking levels per week were reduced to 21 units for men and 14 units for women. Now the safe limits are 14 units per week regardless of whether someone is male or female.
Perhaps this has been done in the name of equality or to make it easier for men to switch genders and become women without worrying about the reduced alcohol limit.
The most charitable explanation for this absurdly low level is that the nanny state knows we are all going to exceed the recommended level regardless of where it's set so they set it low to keep alcohol consumption down. Their intention was to make us feel so guilty we become abstemious instead of rampant alcoholics.
Comment: Pretty much all the science connecting most levels of drinking to any form of ill health is bunk, i.e., there is no connection. Iain McGilchrist summarizes and analyzes this evidence in an appendix in his book The Matter with Things. The main conclusions: there is no known risk, and perhaps even some benefits, associated with responsible drinking.