If you are accepting stock or stock options as compensation, that's generally coming in lieu of cash. Maybe you had an offer somewhere else with $30k more in salary, but you took this offer instead because the projected value of the stock made the total compensation higher. If you sell your stock after 4 years for $50k, you have taken a $70k loss relative to the other offer.
I’d love to count profits and losses relative to the best possible outcome in hindsight rather than the difference between what was spent to obtain an asset vs. what I got for it, but generally that’s not how the IRS sees things. A loss is not relative like that.
I'm not quite sure what you're saying, but RSUs are only taxable at vesting, and are taxed based on their market value at vesting. If the companies stock is worth less per unit, then you are taxed less.
