I've had some people (in person) get very emotional in their defense of sharkbites- one flat out told me off, then he had a leak that took out his entire bathroom wall and floor. To be fair, it's not a 100% failure rate since they sell them in stores and people use them daily, but that 1% or 0.1% that fails could flood a house. Do they work in ideal circumstances? Sure. But there are so many extra failure modes to consider - ID/OD tolerance stack, seal degradation, ovality, seal surface condition, spring rate temp fluctuations, etc. All things I encountered dealing with PTC fittings over the years.
And you are 100% right, solder and crimp connections can leak as well- usually by improper technique and not necessarily by component design failure modes.
Propress is very reliable- I used to use that for coolant manifolds for weld systems - I'd have gone that route on my home projects if I had the $1400 tool