The only security and privacy settings for apps are what the operating system offers. Because you are voluntarily installing the app there’s a certain amount of assumed trust. Many apps abuse that trust and do things the user never really agreed to. Especially around tracking. Browsers also have to comply with the opening system security, but because the websites you visited are rarely fully trusted they tend to guard privacy and security better. And many people use browser extensions to enhance their security.

“What about YouTube? Just use the web version?” Web versions are almost always more secure than the mobile app version of any app. The browser provides more security enforcement than app security.