They will just roll it back eventually.

Capitalists will always try, which means that leftists will be forced into the position of either wasting effort defending those hard-fought-for rights, or be discredited by their failure to do so (see: literally every leftist critique and analysis of popularity of mainstream parties in Western democracies for the past 40 years).

It doesn't mean that what has been gained is doomed, and certainly not that it's worthless. But it does mean that as long as capitalism lives, it will always fight against everything that's been torn from it.

Tear if there's nothing more to be done at a given moment. But kill it if you can.