Many old recipes use wildly imprecise measuresments, ingredients or tools that no longer even exist, and frankly...are bland.
We have access today to so many more ingredients than in the past, and most modern recipes are much more flavorful as a result.
I think we really take for granted the globalisation of foods and spices.
Editing based on a reply:
This is also survivorship bias. Basically, any old recipe worth keeping is still being printed and/or improved upon in today's recipes.