So the SAR people know where to come and look
Look for what? Are you planning on crashing? If misfortune strikes, besides being the unluckiest guy on the planet you have two beacons right? One fixed and one portable. Plus you have tucker and water right? Hopefully a book as well. If you are so worried about the worst how do you get to the airport?
Also makes it much easier when you want to enter CTA
This is total BS for VFR. If I turn up unannounced at a VFR reporting point with no plan just one minute ahead of you with your plan in the system I will get the clearance first. I never file VFR plans, I always get quick VFR clearances and I fly VFR in and out of CTA often.