Yes and this also means it can happen given an economic crisis or crisis of legitimacy, proper organizing and the right balance of power between classes.
it isn't a spontaneous thing that occurs once a certain threshold of suffering is reached.
Absolutely! It's weird how often this simplistic "threshold of suffering" view of revolutions is just assumed without any theoretical basis. It explicitly goes against Lenin who rejected spontaneity and insisted on organizing.
A historic materialist analysis of revolutions does not rely on anything as subjective as suffering. It is concerned with objective contradictions inherent in the mode of production, class analysis, class consciousness and organizing. And no, suffering alone does not suffice to create class consciousness. Without organizing it can lead to despair, passivity or fragmented resistance.
In a successful revolution, seeds of class consciousness lead to political action which leads to more class consciousness which leads to more action and so on.
And those seeds are planted right now in the boring everyday struggle. In every strike, protest and action. And organizing them builds structures and alliances from which a revolutionary potential might someday emerge.
Capitalism is not sustainable and keeps producing crisis and moments that can be captured. History is full of those moments when the ruling class seemed invincible - right up until they were overthrown.
Private space. I used to share one room with my siblings. It was alright as a child, but I don't want to go back. And I know that many families around the world have very little space for two, three or four generations living under a roof.