But the boycott is still an important part of the social movement, isn’t it? Even if, as in the Delano Grape Strike, it takes a decade or more to force change, with plenty of activists disappearing, arrested, tortured, or killed.
That’s a hugely disingenuous counterargument. It doesn’t so much move the goalposts as sets them on fire over a pile of explosives and puts them somewhere in low orbit.
To that question the genuine answer is “what the OP is proposing is not a boycott”, then.
None of these “don’t support them with your money” online liberal fantasies are boycotts by the standards you’re setting. If anything, going back to those examples to get a grasp on what an actual boycott looks like in the context of larger action only exposes to what degree this nonsense isn’t that.