The sad part is if we’re already screwed it defeats the argument of doing much of anything anyway so everyone continues doing what they were going to do anyway.
I think you and the parent are both correct. If we are “screwed” (I.e no action will prevent runaway warming) then any response to prevent warming is pointless. However you are correct that being “screwed” or not is a false binary (we don’t know if warming is reversible but it is likely we can make a positive change and avoid runaway).
