Simply because good encryption tends to be slow, making the app unproductive imo.
gocryptfs is very fast for me. i have a file with about 5600 lines and i detect no difference when opening it under encryption and not under encryption. but in gocryptfs each file is encrypted separately . so you could get some information about the directory structure. but the name of the files and folders is encrypted (“archive” for example turns into something like “AaL6P86WWMnqQkMYnsRBXg”).
It’s pretty good for self improvement. I scored kinda high on neuroticism but after learning some psychology stuff like mindfulness/meditation/neuroplasticity/stoicism/ACT i managed to reduce it significantly after about 2.5 years. there was even a study recently that showed how using a app to change your personality and it’s not easy and require serious training like learning a language or a musical instrument. I hope we will get eventually some open source version of that app.
and of course you need to be open to it, humans have a documented bias toward not believing what might hurt there self esteem.