Many of those old recipes on the notecards relied on heavily processed, shelf-stable industrial ingredients from a century ago that few people would use today. The recipes were commonly disseminated by companies as a form of marketing for their product. We have unimaginably superior access to diverse and fresh ingredients today compared to many of the recipes that e.g. my older relatives used.

Modding those recipes to replace the dependency on heavily-processed ingredients with the fresh, less-processed comparables readily available today often produces good results, though it does take more time.