The very simple reason why so many fonts show up in your font menu in InDesign is because you have all those fonts installed and active on your computer system.
To eliminate all those fonts showing up in your font menu, you have two main choices:
(1) Reduce the number of fonts permanently installed on your computer system. Of course you will need to be exceptionally careful not to prune away fonts required by your operating system (Windows or MacOS).
(2) Use a third party font manager to allow selective activating / deactivating of families of fonts or individual fonts. This also will require some discipline on your part.
- Dov