There is no consistent conception of the masses to the left. Traditionally, there is the labor class and the capital class. In the modern left, oppressors and oppressed are typically determined by identity group, but the game is the same. To win the game of leftism, you better pray that you're in the "masses."
True. A Marxist will have a different conception of the masses from an anarchist (even though the intersection is usually pretty large). But I fail to see what that has to do with anything. There is no game of leftism. The goal is to free people from the tyranny of capitalism and fascism (marxists might emphasize the former while anarchists the latter).
Leftists generally accept rich folks sympathetic to the cause, even though they technically don’t belong to the masses. For example Marxists and anarchists alike generally accept Henry David Thoreau and Leo Tolstoy as leftists (even though the latter was born into great wealth), and leftists generally accept Dan Price (#DanPriceSeattle on twitter) even though he is a boss (i.e. not off the masses).
It is not to free people, it is to free the abstract idea of people. This is how leftists are as tyrannical as everyone. They have a romantic idea of the poor which is not tied to their actual existence or wants, and act on it. Too often, it is just a way to morally justify their own wants or desires. Any evil can be justified if it helps a faceless mass of people.
It is actually quite fun to read Dostoevsky’s Idiot with that in mind that Dostoevsky might have written Prince Myshkin (the Idiot) with Leo Tolstoy in mind. Dostoevsky was very much not a man of means, whereas Tolstoy literally came from a line of nobility. To Dostoevsky, Tolstoy’s talk of the impoverished must have sounded like he had no idea what he was talking about.
That being said, I do think that romanticism of the poor is a really old school mentality, maybe some boomers sometimes still engage in it, but I doubt that you’ll find contemporary leftists engaging in it. Today’s left is much more AOC and Greta Thunberg complaining about how shitty life is for the poor (with a substantial retweet history each backing up poor people calling for it).
There is no game of leftism? The game is for the oppressed class to take power from the oppressor class. Who fits into which of those classes is a contentious issue, though as I said, more frequently predicated on identity than anything else.
Also, to be free of the "tyranny of capitalism and fascism," I hope that those are two different categories. Capitalism and fascism are near polar opposites.
It's also important to understand that leftism necessarily ushers in tyranny. It is impossible, not just in practice, but in theory, for leftism to be implemented without an authoritarian state. If you attempt to get around this constraint, it will only be by you failing to describe a state whose outcomes will fall within the objectives of leftism, or by describing an authoritarian state by any other name (syndicates, guilds, unions).