It's less that it's illegal/impossible and more that it's not in the interests of the company in the long run. Say you do that, then what? If you screw over the seed investors, they are probably are going to tell the series A (and B, C, etc) investors that you screwed them over, and its going to be a lot harder to impossible to raise the next rounds. Plus who would want to invest in a company when the founder already screwed over the last investors. The only way that it could work is if you are able to grow the company indefinitely without raising more money (See Toptal).
Basically, you are exchanging all the goodwill and ability to raise in the future for a small percentage of equity. Not a great trade, if you ask me.
Basically, you are exchanging all the goodwill and ability to raise in the future for a small percentage of equity. Not a great trade, if you ask me.