That may be true of some Chinese companies. But I am quite certain battery manufacturers like EVE, CATL, Lishen and the other big ones including Samsung and LG stick by whatever they document in their spec sheets. There have been people post on this forum who have good functioning cells after 10 plus years in service.Do you think it’s in the best interest of a Chinese manufacturer to have his product last as long as possible? Well if you do I have a fortune cookie factory I want to sell you so that all your dreams can come true.
I have a pair of Valence batteries and the cells were manufactured in China. They are connected in parallel and still produce 95% capacity even though they are around 10 years old. That is a dream come true and I did not need a fortune cookie to make it happen...