I had an archaeologist tell me a few months ago that his theory is that an Indian hunted with a certain style of point until he saw that Running Bear was getting all the girls, because he brought home more game. Indian #1 would then modify his points or copy Running Bear's points so that he could be successful. Success meant life, so wholesale changes were not easily accepted. That's why the offshoots of different points carried on for thousands of years. That is paraphrased, but his general words.
Some points worked better than others in different situations with different types of game, atlatl species, etc. So a Dalton point, which supposedly dates back to around 11,000 -8500 years BP, may in fact have even been used historically rather than prehistorically if certain individuals or clans were successful. It's easy for anthros and arch's to lump things together to fit their narrative, but when you find a mixed bag of points from supposed different eras it makes you pause. We recently found a cache of points ranging from Kirk Stemmed and Kirk serrated to Adenas, Etleys and all points in between. There were approximately 20 or so within a few feet of each other, and the generally accepted ages of them were from 9500 to 1300 BP. Were they handed down? Maybe. Or maybe they were what worked the best.
Questions like yours are what keep me and others interested in this stuff!