Early in the pandemic, when we had no vaccines or therapeutics, doctors had a kitchen sink approach to COVID. They threw in every reasonable treatment in their arsenal to see what worked. This is how corticosteroids and monoclonal antibodies became standards of care. Some leads that initially seemed promising or had a reasonable theory behind trying, like high dose NSAIDs, interferons, antivirals, hydroxychloroquine, fluvoxamine, and ivermectin, failed in well-designed studies. It's not like these patients were denied standard of care treatment, though, simply because there was no standard of care at the time. So, were they "guinea pigs"? I guess that depends on your definition, or whether you think volunteering for a trial is a good or bad thing.
I hope that we develop better treatments going forward. Corticosteroids and monoclonal antibodies are useful tools, but their benefits aren't game-changers either. The former is only useful on hospitalized patients who are already very sick, and the latter is very expensive, has a rather narrow clinical indication, and is difficult to scale up for everyone who might benefit (despite what a certain governor likes to tout). The Holy Grail will be a well-tolerated oral antiviral medication that can stop an infection in its tracks.