The way the Google support page ("Android 8.1 and up") is written suggests that this option may have been only available in third-party ROMs:
Disable apps that came with your phone
You can’t delete some system apps that came pre-installed on your Android phone. But on some phones, you can turn them off so that they won't show on the list of apps on your phone. To learn how to disable apps, contact your device manufacturer.
I don't personally have an issue with bloatware as I run LineageOS, but temporarily turning off apps would have often been beneficial for various reasons (some, while useful, are rarely used and may run at boot; issues with the latest update and no roll-back option).