The current antitrust laws work fine, and they work for the benefit of consumers. However, if these laws are changed so they can be used to punish large tech businesses, then gone are the days of free apps, free search, free messaging, free delivery, and expanded consumer choice. Furthermore, by removing the consumer welfare standard, businesses across the spectrum can be easily targeted for ideological and political reasons.
Then, antitrust protections once designed to protect consumers are guaranteed to harm them. See the Town Hall for this entire piece.