If there’s moisture in the filament it vaporises in the extruder, causing steam bubbles that expand and disrupt the laying down of plastic, usually causing inconsistent extrusion lines (which itself causes poor layer adhesion). Some of the filament may end up being heated in the extruder slightly longer than other bits depending on these steam bubbles, which can cause overheating issues like stringing and oozing, etc…
Not to mention that filament that has absorbed water tends to become more brittle, which can lead to the filament snapping off before reaching the extruder. As a result, a filament’s shelf-life is usually dictated by how quickly it absorbs moisture (and also whether UV from the sun weakens it at all, but that’s a lot easier to manage).
Strong disagree. I ran non-ECC memory on my server and services would unexpectedly crash maybe once per week. Over the span of a year I had two databases get corrupted that cost me a lot of time to fix. I tried swapping sticks but it happened with all of them. I switched to ECC memory and the problems disappeared. I needed more memory anyway and the price delta for ECC was about $100. I didn’t have to swap CPUs or anything, AMD desktop CPUs and chipsets support it out of the box. ECC memory is absolutely worth it.