As a counterpoint that's not uniformly distributed globally, the incidence is much lower in Northern Europe including UK where OP is from.

As a counter-counterpoint, you assume OP's ethnicity is Northern European just because he lives in the UK.

That might be the most common reason globally, but not necessarily in the UK where only 5% are intolerant. Many of those can tolerate small amounts such as you'd put in tea/coffee.

Lactose-free dairy products are readily available.