“Of course my Presidential vote won’t matter...”
Then why vote?
That was an imprecise statement on my part. More accurately, my vote won't affect the outcome in California. Biden will still win California by several million votes, albeit less than Hillary's 4.3 million winning California margin in 2016.
However, my vote matters as a symbolic expression of my political preferences, and as a continuation of my unbroken record of voting in every election since 1970 when I first became eligible to do so.