There's "small print that taketh away" in every warranty. Sharkbite has a 25 year warranty on their fittings... But, when you read the warranty carefully, it says, "When used with Sharkbite tubing"... Lowe's and Home Depot don't carry "Sharkbite tubing" and that's not what's used in any Keystone water system, so the "Sharkbite warranty" is voided before you even get started....
I'm not saying that Sharkbite fittings aren't "first rate and reliable", just that there are conditions stated in their warranty, just as there are conditions on almost every warranty.
IMO, the problem with travel trailer plumbing is significantly different from home (S&B) plumbing. That difference: Home plumbing doesn't typically use plastic fittings, vibrate down the road, twisting and pulling against itself. Most S&B plumbing is secured to the studs/rafters/joists and the only movement it's subjected to is "water hammer" or expansion/contraction from temperature changes. Most travel trailers are subject to significant twisting and bouncing during towing. That movement, over time, puts an increased stress on the plastic fittings (lowest bid items) which are often installed "under stress" as the plumbing is pushed through a hole in a cabinet and "torqued around the curve" rather than installed using appropriate fittings to prevent the stress from bending. As an example, that plastic 1/2" elbow that's installed, then the PEX tubing pulled back to 45 degrees to connect to the faucet stem. There's the plastic fitting with the cone washer that's sharing the stressed load along with the elbow that's installed to hopefully prevent the PEX from kinking. All that stress will probably survive the 45 or 50 PSI and likely the 60 PSI water pressures....
BUT: connect to the city water tap at Tourist Park in Marquette, MI, and when "quitting time comes" at the city garage that shares the main water line (and is located at the back fence of the campground) the water pressure that's normally 60-70 PSI can increase to 110-120 PSI during the evening hours. That increase is why there's a recommendation to always use a pressure regulator on any connection to the campground water supply. Some ignore that recommendation. Some of them never knew there might be a problem, but if you're "the one with a weak, stressed plastic elbow" .....