In fact “concentration camp” is largely a misnomer. The sizable majority of Holocaust victims were killed in extermination camps, like Treblinka. These never even purported to hold any prisoner population, and simply murdered all prisoners immediately upon arrival.
The British have no shortage of problems. But nothing in their history is even remotely comparable to Hitler.
The main visible difference nowadays is that Germans of today are hyper-aware of the atrocities committed in the past by their ancestors. Britons are often either ignorant of theirs or are proud of them.
Warning: Disturbing images
[1]https://en.wikipedia.org/wiki/Second_Boer_War_concentration_...
[2]https://en.wikipedia.org/wiki/Children_in_the_Holocaust#/med...
In contrast, Nazi leadership sat in a seaside resort and meticulously planned out the industrial mass execution of millions of people. The entire regime from Hitler down was involved. So while, I'd agree there's a moral equivalence between Kitchener and Heydrich, the Nazi regime itself is far more guilty than the British Empire.
[1] https://www.history.com/this-day-in-history/boer-war-begins-...
No wait! The British are worse, because majority have not accepted the horrors that British empire has brought to many people... Not the least being be Bengal Famine of 1943. There's no question that Nazis were evil. Time to realize that many other empires were/are "not benevolent".