By doing what, exactly? Not paying the subscription? Apple isn’t going to interpret that as “oh gee maybe we should stop running ads”, they’ll view it as “this is why we show you ads, so we’re making money off you regardless”.
Voting with your dollars is effective for multi-billionaires and C-suite executives of trillion dollar enterprises. For everyone else, it’s rarely better than cutting off your nose to spite your face – you might feel better, but it won’t change the behavior of the other party.