I'm not sure if you're making this argument in good faith, but just in case. The iranian government has no love for socialists/anarchists many of whom have been executed (especially in the years after the islamic revolution) or live in exile.
From what politically active iranian comrades told me (in exile), the social movement in Iran is very much alive and there is an underground left-wing scene (for example an anarchist/punk scene). Likewise, the Jin Jiyan Azadi movement following the execution of Mahsa Amini is very much on the left wing, inspired by Rojava's democratic confederalism.
From a western european perspective (eg. me), the dilemma is not the one you presented. Sure some fringe groups have campist [1] tendencies, but that's far from representing the Left as a whole (which has historical links with the anti-islamist left-wing in Iran). The dilemma would be: how to support a people's revolution without supporting our own western empires making the situation even worse? The most moderate/imperialist liberals have learnt the lessons from the Taliban's comeback in Afghanistan and the return of black slavery in Libya: we can do better than bomb a foreign people.
Still, the demonstrations here in France supporting the uprising in Iran (at least those who are not organized by the fascists trying to bring the Shah's son to the throne) pretty much have the same crowd as the pro-palestinian demonstrations. I'd be curious, apart from obvious propaganda, where you'd find the idea that left-wingers wouldn't support overthrowing a tyrannical government.
(cue history course about the history of secularism and why opposing islamophobia is not incompatible with opposing islamism or any theological tyranny)