With so many options popping up left and right, choosing one seems like a bad idea. Better options are coming out every month or so.

Save your notes in a folder on your device. When you have a use case for interacting with a tool, upload the parts of your notes and references that are relevant.

This way you can have any kind of file & also use it how you want.

I tried a ton of services. Most of them are extremely immature and not ready for you to dive in and use them as a real second brain.

notion seems okay since you also use it for work.

TwinMind

Train your own brain first. Or good luck with dementia