I understand where you're coming from, but I'm not entirely sure I agree.
The British policing system is based on Peelian principles - policing by consent - in a way that other police forces around the world are not. It's why they don't routinely carry guns, for example.
I've been in policing for 20+ years, not as an officer but as a senior staff member. In my experience, there's always been a tension even within policing about whether it's a 'force' or a 'service'. The authoritarian macho types are attracted to the tactical firearms units and the dog sections etc, whereas others gravitate towards neighbourhood policing (utilising different skills/ personalities) and child protection etc. The units you'll encounter on demos (other than the large ones where officers are drafted in from other forces) are generally the alpha males, there to not think twice about using force. Even within the police service, it's acknowledged that this tension exists. In other words, policing reflects society as a whole, with roles that suit a variety of personalities.
Whenever I watch things like 24 Hours in Police Custody, I'm always struck by how well the Custody staff treat the person they're booking in, without prejudice. Yes, I know they're being filmed, they know they're being filmed. But having once in my career overseen an independent Custody visiting scheme (normal people who volunteer to visit custody suites unannounced and speak to detainees about their treatment), I can tell you that, in my local force at least, the vast majority of those detained - some very hardened criminals - stated they were treated fairly and with dignity, as is right when our judicial system is founded on innocent until proven guilty.
When I've been on large marches in London (e.g. the Stop Brexit march) there were no arrests, a carnival atmosphere, and police officers chatting happily to protesters.
Now, as for the Met. Even within policing, the Met has a terrible reputation. That's not to say that these officers don't exist in other forces (they do, I've sat on professional standards committees where they've thrown the book at them), but just that it's the largest police force in the UK, policing a densely populated territory, and comes with quite a significant number of challenges as a result. I mean, they literally threw Cressida Dick under a bus for not dealing with the problems quickly enough and replaced her with.... another man - who, similarly it seems, has failed to root out the culture that seems to still prevail, despite his obvious professional credentials.
I've begun watching the documentary and it makes me sick to the stomach, precisely because I've always been exceptionally proud to work with, for the most part, some extremely caring, hard working people, dedicated to protecting people from harm. This kind of coverage does them all a huge disservice and damages the trust and confidence needed to rely on policing 'by consent' in this country.
Police forces all have problems, because racism and misogyny is again gathering pace in society more generally - and recruitment practices focus on drawing officers from a wide variety of backgrounds in order to try to reflect societal makeup. That comes with risks, as well as benefits. What they need to get better at is utilising technology and social media monitoring better within the vetting process, so that those who pose the most significant risk (by virtue of either their associates or views) are weeded out at the earliest opportunity. The police cannot afford to have officers like this damaging public trust.
Op, I don't feel remotely sorry for these individuals for all the reasons I've stated.
And I guarantee that I will turn up to work today and be met with eyerolls of "yep, it's the Met again".