Is it normal for a laptop battery to break / empty / defective after 6 years of intensive use.
It is entirely possible. Even with the best care, the shelf life is limited. Probably also varies from manufacturer to manufacturer.
6 years is very good, most of them are finished much earlier.
Yes, if you have used the battery intensively or if it is of a different quality. That varies a lot these days. One battery on my MacBook lasted 13 years. ^^
I agree. Usually much earlier. The manufacturers can now design the products in such a way that they break e.g. 1 month after the warranty has expired. This is done on purpose.
It's the same with batteries for smartphones and tablets
6 years battery? Congratulations - that's probably a good one. Don't expect a new laptop to last just as long.