In fact, nothing
If the chain is PoW (like Bitcoin, old Ethereum), the user can mine the coin with her computing resources. If the chain is PoS (like Ethereum, Incognito), the user should buy some coins from somebody by using means other than the chain. If Ethereum hadn’t been forked from a previous chain and not listed in the exchanges widely, new Ethereum would also faced the issue in Incognito. To solve the problem, some ecosystems prefer the airdrop (Incognito also did this at mainnet launch), some prefer ICO-like sales.
Currently, no need to airdrop (automatic airdrop is just the team’s good will) or something like that for PRV since it is listed in both PancakeSwap & Uniswap. Ok, there is no much liquidity but even 100 PRV can be bought at a reasonable price from PancakeSwap. That amount will be your egg to have a chicken Btw, yes, PRV can be shielded/unshielded from/to BSC and Ethereum.
Let me list the direct addresses of those pairs:
https://pancakeswap.finance/swap?outputCurrency=0xB64fde8f199F073F41c132B9eC7aD5b61De0B1B7
https://app.uniswap.org/#/swap?outputCurrency=0xB64fde8f199F073F41c132B9eC7aD5b61De0B1B7 (so low liquidity)