Apple has said that there’s no point - the system will dynamically stop applications (and/or their scenes), and force-quitting will remove the app’s data from memory, potentially forcing it to reload data at the next launch, when it might not actually be necessary.
In general, I don’t force-quit apps unless I’m experiencing a problem (e.g. an app that’s hung or is consuming too much CPU power, and is therefore making the phone hot.)
See also Apple’s support page about restarting apps: