Capitalism. In that it's probably the vaguest of answers but it's not one specific thing but a culmination of things.
I've been in the workforce in multiple different countries and it all runs to the same drumbeat: profit at the expense of everything else. I've worked factory in at least a dozen different sectors, I've worked in aviation, retail, shit I was even in the military and it all has the same song and dance.
I'm 40, yeah? Growing up it was heralded as the saviour of all things, socialism bad and all of that. However it has always boiled down to the expendability of the employee no matter how good at what they do they are. The fact regardless where on a whim you can either be terminated or pushed out of the place where you make money to put food on the table, because you're too expensive or the company needs to save money(assuredly in the wrong place) upsets me greatly, to the point of blind rage.
I don't hate people who ascribe to capitalism's siren song, I'm disappointed in them. Disappointed that they put a coin or banknote above the health and wellbeing of another sentient being. Disappointed and dissatisfied with the lack of long-term thinking, planning and problem solving. Growing up I was so often told by my father that investing in the workforce is absolutely the best course of action, that's where the true path to success is, not cutting budget or outsourcing or Draconian work hours and conditions.
I wasn't radicalised by losing my job time and time again, I was radicalised by society shoving a loaded magazine fed pistol in it's mouth and pulling the trigger, thinking that nothing bad would happen.
When it's conversation about politics I'm generally very mum or quiet, and people often confuse that with apathy or disinterest or having something to hide, it's no the case. It's the opposite, I often don't have much to say that hasn't been said already or what I'm going to say is something that they don't want to hear because it's often if not always to the beat of: don't complain do something, do something loud aggressive something to send a message. It's not a rare occurrence that I have a moment in my thoughts where I'm sitting there wanting to scream, instead of just pointing out how shitty xy asshole is: "fucking kill the bastard! Put that fucker in the ground!"
So yeah. That's what radicalised me.