Does acquiring companies for injecting 'young blood' actually work? I feel an acquisition means the founders and early employees would want to kick back and rel

Does acquiring companies for injecting 'young blood' actually work? I feel an acquisition means the founders and early employees would want to kick back and relax in the comfort of a big company job for a while. The examples I've seen are where they wait out their vesting period, and then quit and start their own company.