More power to a fishkeeper willing to chase and catch 8 fish in a 75 gallon tank to administer a solution to each with an eye dropper daily. Whew.
Sure, obviously not the first option I'd go to. But it's worth the trouble if other treatments aren't working and you have prized or valuable fish. I've gone to a lot more trouble than that for fish I valued, including driving for hours to get the right meds, etc.
Also, there's a relatively simple solution for that, something I've done often for difficult to catch fish, which is to use a tank divider or something similar to shepherd fish into one end of the tank. Makes them
much easier to catch and a lot less stress (on you and them) than chasing them all over the tank. And, yes, in a heavily scaped tank you may have to temporarily remove some items, but, again, imo it's worth it if that's what it takes.
People catch fish out of their tanks all the time for numerous reasons, strip eggs or fry, move them to new tank or a hospital tank, change tank from one type of fish to another, remove a troublemaker, the list goes on. The merit of a treatment as an alternative when other means are failing shouldn't stand or fall based on it being a bit of a chore.