There are two problems, here.

The first is that Brazil's election was between soveriegnty and vassalization. The US election will maintain imperialism, will maintain capitalism, will maintain settler-colonialism, will maintain the genocides on Palestine and Cuba, and more. Neither mainstream party fundamentally challenges the dynamic. Brazil on the other hand was fighting between BRICS, and US subjugation. Not socialism, not capitalism, but their place in the world economy, which did change.

The second is that you cannot reform capitalism into socialism, not even if you elect people that genuinely want socialism. The capitalist state is not a neutral entity distinct from the economy, but the part of the overall system made to maintain it. Even if you elected every single self-described socialist, you still would need revolution in order to smash and replace the capitalist state with a worker state.

We don't want revolution. We need one anyways. If we could do this peacefully, then Marxists would all be reformists, but to believe in reformism is to reject how we understand capitalism and the state, how class struggle functions, the entire underlying thesis for socialism to begin with. The good news is that every socialist revolution that has solidified worker power has managed to dramatically uplift the lives of the working class. A better world is possible, and our predecessors showed us how.

If we cling to reformism, this will at most leave us with social democracy, which quickly turns to fascism during crisis of profitability. It will maintain imperialism, as is intrinsic to the monopoly stage of capitalism. It will continue to prevent the working class from actually having power.