Curt, while I agree with your point overall, I feel uneasy every time this is brought up. Because there is something called Total Addressable Market, which is not infinite. Suppose there is a path for Tesla to achieve a $1T market cap in 10-15 years. Tesla can theoretically raise $50B by doubling the number of outstanding shares right now to accelerate the path towards that goal. In that scenario, we would still own the same size slice of pie as before (just like you said), but Tesla would need to achieve a $2T cap in the same timeframe for shareholders to have the same percentage gain.
Another way to look at it is, if we assume Tesla will be worth a lot more in the future, then it's not a good bargain for Tesla to sell shares at the present. Imagine if Tesla raised $1B when they were worth only $3B. It would be much less beneficial to shareholders than if Tesla raised the same $1B when they are worth $30B. Thus, as a shareholder, I view secondary share offerings as something that should be avoided as much as possible.