Or alternatively, call out the worst offenders who try to undermine the whole enterprise first(e.g. Mercola), move on to those that abuse the notion of science (e.g. the tobacco industry using paid researchers to cherry pick data), then after that you can deal with the ignorant and those that present information wrongly (e.g. the news). As far as “corporations” go, I don’t know what that means. Pfizer? They make medicine that is backed by science. Pricing practices aside, they’re far from the worst end of the spectrum. Not all bad actors are equally bad, and it only muddies the waters to paint them with the same brush.
It’s not hard to define what “truth” means in the context of science. There are “things that have held up against the most rigorous scientific testing we have as of today”, and “other”. The “other” category can include things that are completely disproved (e.g. phrenology) or things that are experimental but not proven or disproved yet (e.g. some eastern medicines) but ultimately those are the only two types of information.
Vaccines do more good than bad. Chemotherapy is the most reliable treatment we have for a lot of cancers. These aren’t things open to opinion. If you tell people they’re wrong, you’re moving people away from truth.