Recipes were mostly complete before the internet was even invented
But the context around them has changed a lot. E.g.
1. Newer devices have made it easier to do certain sorts of cooking, but it needs to modify the recipe ever so slightly for best results. E.g. Microwaves have become more common, air fryers.
2. People doing 2 jobs in the last few decades are now not looking for BEST possible taste like the housewives of 1970s, but acceptable taste, hints at once a week meal prep work, and quick to make recipes.
3. Availability of different types of partially cooked, precooked etc. ingredients has changed. Spam, corned beef, certain sauces that were common earlier has now given way to a much wider variety of intermediate food ingredients. These need to be explained in the newer recipes in a new way.
4. Fusion. A lot more eastern spices are now available in the west, and western ones in the east. Many of them make sense in recipes from far away, if only one is ready for newer experiences. A recipe writer who has tried a few and suggests successful combination is far more important now than when the internet was invented in the 1950s.