It would seem so... I can tell you judging from my own fairly lengthy experience with lithium based batteries, once they get down to the 50% range they can crap out on you completely at almost any time. They do not typically linger for very long once they start to fail. And you also may end up with cells that start overheating and put the entire battery at risk.
People with skills, training and equipment can sometimes squeeze a little more life out of them, but this is typically more along the lines of adding sawdust to motor oil to hide a rod that is knocking or crankshaft that has main bearings that are shot.
This is one of the primary reasons China has junkyards filled with abandoned electric vehicles. Believe me they are more adept at using crap that is ready to be retired than people here are.
Is your experience with lithium batteries in vehicles? I’m not sure phones, laptops, and cordless drills are good predictors of how the batteries in EVs will behave as they age, even though they all contain lithium. It could be that they are, but it wouldn’t surprise me if they’re not. It would be interesting to see a good analysis of how EV batteries are going to perform as they age. I don’t know enough of the circumstances behind the Chinese junkyards to tell if their existence means anything. The Chinese have oddball stuff like ghost cities going on over there that seem peculiar to their quasi-communist economy and its massive misallocations of resources. Maybe these EV graveyards are a similar story.