Welcome to Android Central! I think what you're doing is uninstalling updates from preinstalled system apps. You typically can't completely remove preinstalled apps. You can uninstall updates (which usually leads to a message asking if you want to replace it with the factory installed version), and then if possible, you can Disable the app, which prevents it from opening into RAM or updating to a higher version again.
It's generally not a good idea to uninstall or disable apps indiscriminately if you don't know what they're for. That might cause more problems, and then you'll be right back here asking for halp, wondering why your phone is bugging out.
