Smaller ad-tech firms are raising competition concerns over Google's long-brewing cookies alternative, Privacy Sandbox, at a time when the internet giant's digital ads business is already under U.S. and UK scrutiny.

The U.S. and UK regulators suspect that Privacy Sandbox, which has been in the making for five years, could give Google too much control over the digital advertising market, harming competition.

Google's dominance through Chrome and Android platforms, which command the lion's share of internet users, makes adapting to Privacy Sandbox a critical necessity for ad-tech firms.

However, the investigations and potential technology development delays are hurting smaller ad-tech firms, as the burgeoning costs due to adoption delays for Privacy Sandbox will put them at a disadvantage against well-heeled rivals.