The reason you only get to vote for the "lesser of two evils" is because you don't participate in primaries (assuming you are talking about the US system here). If MAGA can get a psycho like Trump to be their party nominee, you can get your kind of psycho nominated as well.
Primaries are where you actually get a chance to express what kind of candidate you want. Hell, you can even run for office! Generals are where you hold your nose and vote for the lesser of two evils because otherwise it's an automatic vote for the worst of the two evils.
I agree voting seems pointless sometimes. But it's still important. But it's a lever of power you have access to and nobody can take it away from you no. And you can spend the 364 other days of the year impacting politics in other ways.