Why is the British police allowed to let rapists go free?

For years and years, especially about ten years ago, the far-leftist feminists went on and on and on about how there's a rape culture in our society, where men raping women is seen as a lesser of a crime and where police officers and other officials routinely disbelieve women who have been raped and let rapists go free.

For years and years this was considered by far-leftist social justice warriors as one of the biggest crimes in modern western society. There were huge campaigns and protests to rectify this, and many times there were huge over-reactions to alleged rape cases, especially in university campuses (back ten or so years ago there were several infamous high-profile cases of far-leftist university students organizing violent protests over rape accusations that in the end turned out to be completely false, and the accused men completely innocent of any wrongdoing.)

One of the slogans that feminists of the time loved to push was "listen and believe". Women who claim to have been raped should be listened and their word taken seriously, and the starting point of any investigation should be to assume that she's telling the truth. Letting a rapist go free was considered one of the greatest injustices in this world.

Some far-leftist feminists even went so far as to express that an accused man should be convicted even if he's proven innocent (the logic being that if he isn't convicted that gives ammunition to the "enemy", to the "right-wingers" who want to doubt women and think that they are just a bunch of liars, or even that they deserve to get raped.) In other words, men are expendable and even innocent men should be used as tools for the bigger goal of stopping rape. Their own personal suffering is a small price to pay (and in fact doesn't even matter; they are men, and thus their wellbeing doesn't matter).

So, in this light, why is it that the British police is allowed to let hundreds and hundreds of proven rapists and sex offenders go free without any sort of punishment, or even a mark in their criminal records, without any sort of massive protest?

Where are all the feminists and leftist activists demanding justice? Where are all the protests? Where's the outrage, other than just a few newspaper articles? Where are all the social justice warriors marching the streets and breaking windows because of this extreme injustice and display of patriarchy and rape culture?

Why is the British police exempt? What makes them different? I thought that the left hates the police.