Configuring the network as metered is the best way to control it on Android. On Android 12 you can configure the network after you've connected to it. Select the gear icon next to the network name under the internet settings (settings -> Network & internet -> Internet) then click on the pencil icon to edit the network settings. Pull down "Advanced settings" and change the "Metered" setting to "Treat as metered"
Once you've configured the network disable the following.
Disable Google Account sync
Settings -> Passwords & accounts -> Automatically sync app data
Disable Google Photo sync
Photos -> User image -> photos settings -> Back up & sync ->Back up & sync
Disable Play store auto-update/auto play
Play Store -> User -> Settings -> General -> Network preferences -> Auto-update apps
Play Store -> User -> Settings -> General -> Network preferences -> Auto-play videos
Turn on Data Saver (This is what enforces the metered network settings. Make sure to do this)
Settings -> Network & internet -> Data Saver
After turning on data saver configure the apps you wish to have unrestricted access to the network by clicking on the "Unrestricted data" field. I give unrestricted access to Carrier Services,
Disney Cruise Line Navigator, and Google Play Services
Disable Wi-Fi calling
Settings -> Network & internet -> Calls & SMS -> Wi-Fi calling
If you use WhatsApp Disable the google drive backup and auto media download
Settings -> Chats -> Chat backup -> Back up to Google Drive
Settings -> Storage and data -> When connected on Wi-Fi