If the founders and investors all own SAFE notes, how bad is that for common stock option holders?

I’m interested in joining a startup from San Francisco for a modest pay in exchange for 0.75% of equity (stock options). There has been one round valuing the company at $22 million. The serial founders told me that after this round they own SAFE notes (the founders co-invested themselves), and the investors too.

My understanding is that SAFE notes will get converted to preferred stock at a later funding round and that they dilute common stock. So while they are offering me 0.75%, I think I have to account for an unknown number of SAFE notes suddenly getting converted and diluting the common stock holders. Is that true?