Well, sharkbite fittings depend on an O ring for integrity under pressure, and their teeth biting into the pipe to resist push out. Mine are installed so they cant push out, but there is still the O ring. I have to say that my confidence in properly soldered copper, and solvent welded CPVC is much higher, so when I go away for any length of time, I shut off my water main which is a one inch 1/4 turn Plastic Ball Valve. Maybe my confidence will increase over the years, but then so will the age of those O-Rings.
" Most people would rather die than think, and most do " Bertrand Russell