I don't think I've filed a VFR flight plan (in the US) in the last 10 years. I might do if I was doing a cross-country flight where there's a chance of going down truly in the middle of nowhere and out of radio contact, but now that I have a 406 MHz ELT, I'm not even sure about that.
(And to be honest, I don't remember the procedure for opening one, which involves using a frequency that is otherwise never used).
The sole value of a VFR flight plan is that when you don't arrive, they will send out the Search and Rescue to look for you. It has no other purpose or value, neither to the pilot nor to ATC.
I do use flight following for every flight that isn't just a hop to a local airport. That is useful both to me and to ATC.
IFR is a different matter. You can't fly IFR in the US without filing a flight plan. (In theory you can as long as you stay in Class G, but that is impossible in practice).