Raising money after IPO is pretty different because there’s no fantasy element to valuation.
Public companies can raise money by selling shares in a registered direct offering, or doing a PIPE (private investment in public equity). They can even register to sell new shares directly on the market (called ATM). But if there are not enough buyers, it doesn’t help to keep printing shares.
Don’t forget it’s also in the interest of middle managers to lower the productivity of the people at work, who actually add value as well. This decreases the productivity gap and helps to not expose how useless they are.