It's much more complicated than that. For one, you're conflating targeting industries vs targeting individual corporations.
One of the core jobs of the president is deciding which lawbreakers to go after. This is needed because (among other reasons) the government is far too small to enforce every law. In general the President is supposed to set general parameters but not pick specific individuals or companies. Deciding a specific sector's violations are more pressing is squarely within the traditional discretion of the executive branch.
Social Media and Online Retail are big nothings compared to Finance and Health Care. Finance shenanigans cause global recessions and health care is consuming 20% of GDP and growing. Since politicians and journalists love Twitter though, we get to hear more about that instead.
On the other hand, healthcare companies aren't an integral part of a cycle which leads to armed mobs.
The other thing to remember is that healthcare costs, while significant, are both familiar and legal, and the government uses the regulatory powers which Congress has granted it. Finance similarly has existing agencies and laws and while there are periods of lax regulation which end badly most people would say that the problem is regulators choosing not to use their powers or Congress underfunding staffing rather than an unclear question of how to handle a particular problem. In contrast, something like what should be acceptable on social media doesn't have public consensus and runs into thorny constitutional issues. It's understandable that this gets more attention, especially a time when one of the major political parties is making unfounded allegations in an attempt to keep their voters active.
One of the core jobs of the president is deciding which lawbreakers to go after. This is needed because (among other reasons) the government is far too small to enforce every law. In general the President is supposed to set general parameters but not pick specific individuals or companies. Deciding a specific sector's violations are more pressing is squarely within the traditional discretion of the executive branch.