Apps are easier to pull data from than websites even more so if you have an adblocker with tracker blocking. There’s a very good reason websites try to push their apps when you open a mobile site.
It depends by what you mean by "safer". From a privacy standpoint, there probably is little difference if you allow cookies to be set by websites, don't use a VPN, use Facebook's sign-in service on non-Meta websites, or leave Meta-related accounts logged in all the time. If you are worried about device security, the app could be more secure for many reasons (use your favorite search engine if you're interested in finding out the details).