3 prong grounded vs 2 prong AC Adapter/laptop charger

My lenovo AC adapter died (square tip type), I was looking at a replacement and noticed the cord on the input side of the adapter has no grounding prong. My old 65W adapter did have a ground plug, yet this 90W OEM unit has only 2 prongs. I figured I'd upgrade to a 90W adapter just so it doesn't have to work as hard, my old one would get very hot.

I know the tiny/AIO desktop adapters and Thinkpad chargers are interchangeable, same voltage, same connector. That said, the lenovo product page boasts about better reliability (something like 30000 power-on hours vs 8760 for thinkpad chargers), which sounds like upsell baloney to get people away from cheap/available thinkpad chargers.

I started scouring ebay and noticed that some OEM lenovo chargers have a ground plug, some do not, though interestingly most of the cheap "compatible" generic adapters do seem to show a grounded plug.

Does the ground matter on a laptop adapter? From what I can tell the output is just 2 wire DC so it's not as if the ground does anything, at least not for the machine. The chargers are also encased in plastic, yet there must be some EMI or other design consideration that factors in. I still find it odd one adapter would have a ground but a higher amperage one would not.