I don't need all my bikes to be equipped the same. The three bikes that I use the most are also the bikes I am most likely to need lights on, so they have dynamo lights. One of them has an annoying sidewall dynamo, so it's really just an emergency system. I have battery powered lights for the bikes I prefer to keep lightweight. I move the lights between those bikes as needed. This approach lets me balance performance (which I perceive to be superior with dynamo lighting) and cost.