Completely disagree.
I have thousands of hours in airplanes, helicopters and gliders (combined, mostly airplanes), and I still can't say "I have confidence in myself", which I believe equates to complacency. I still worry each and every time I take off in any aircraft for any kind of flight that I'll crash and burn (well maybe not burn in gliders
), one way or another, or at least have a dire emergency and have to deal with it.
Having a CFI on board for an inexperienced pilot is extremely useful, not just for immediate safety, but for future safety, i.e. risk reduction, so it does matter, a lot.
And any pilot going around thinking "when your number is up, it's up" is an accident in the making. The most important aspect of flight safety and risk management is that you, as PIC, can mitigate your risks drastically, starting with training, maintenance, pre-flight planning, inspection, adherence to checklists, proper judgment, etc. IOW, your flying can be essentially as safe as you want it to be.