We have to do it. Some of us have to do it in different ways. Doing small things where you can is all well and good but literally none of us are making a single impact in capitalism by making different choices about how we're forced to participate in it. Focus on tearing it down together rather than picking apart individual choices because those individual choices still result in participating in capitalism.
You're right - we cannot escape capitalism. The various electronic devices we use, the clothes we wear, the food we eat, the power we use in our homes etc. At the same time, as leftists, we must try to reduce the harm we cause at a personal level, while recognizing that this wouldn't end capitalism. Use your phone/laptop etc for longer rather than getting a new one every couple of years. Wear clothes for longer, or get them from non-exploitative labor. For food, don't eat meat. These are all steps you can take that won't end capitalism - but they're all steps that you take if you have a compassionate view of the world.
These are all things we should be doing, that in fact, we can do if we act collectively, but right now we don't have that level of solidarity. So we do what we can as individuals while building towards that solidarity.