Life time warranties do contribute significantly to a buy it for life decision. Lets take automotive tools. I use mainly Gedore tools to maintain my vehicles. A few years ago I found a clapped out, worn, ratchet in a second hand toolbox I bought. Took it to my local dealer to find out about replacing the mechanism and they outright replaced the ratchet with a brand new one. At no cost to me and I was not even the first owner.
My own set Gedore of sockets and spanners are still in perfect condition after 20+ years of use. Yes I paid double store brand prices back in the late 90s for them, but I am sure they will be heirloom tools one day.
It really depends on what you are buying, but lifetime warranties does contribute to the decision.
There is always an element of risk to 3rd party batteries. That said, a reputable supplier that warranties the battery for a period should be fine. In my experience OEM batteries generally lasts longer and use better quality components.
So it is up to you to decide if the price premium is worth it in your use case.