One of the obvious benefits is that they allow firms/corporations to secure long-term finance that will allow them to undertake new projects and grow. This is more so for companies long to expand or diversify. The bigger benefits, however, accrue to investors, who can participate in the growth of these companies by investing in their shares. It becomes a source of wealth creation for them.
The market allows investors easy entry and exit from the shares of any company at a price determined by demand and supply. This imparts tremendous liquidity to the asset class. Besides the ability to buy and sell, investors get access to all the relevant information about the listed companies to make informed decisions. A listed company is required by law to be more transparent and disclose a lot more to shareholders. Stock exchanges and market regulators require listed companies to meet strict disclosure and regulatory requirements.
A listing also means that your stocks will be bought and sold through a very reliable and time-tested clearing mechanism. This way, investors are sure that the stocks they purchase will be delivered to them, even if the counterparty to the transaction does not deliver.