Non-Tender Offer Buyback Options

Hello all - forgive me if there’s resources that I have not located yet but here’s my question - With fewer companies going public and/or taking longer to do that, how are companies solving for employee liquidity? How common are alternative private liquidity programs (for example, company repurchases of stock) and is there a summary of the implications of this (legal, accounting, tax)? (FYI - not looking for tender offers as a solution either). Thanks in advance!