Well, if you really want a power meter, get one by all means.
Having one will not automatically make you a better or faster rider. But then again, it probably will not make you a worse one either. It is just another tool to use.
Remember, years ago before either power meters, or heart rate monitors or even bike computers, there were cyclists who were so good that they were scary. So getting really good can be done without any of that stuff.
A good rider is going to be good pretty much no matter what. A power meter and/or HRM helps get more out of more limited resources, when those limited resources are time and potential rather than money...