https://www.ghacks.net/2020/02/21/google-updates-its-terms-to-include-chrome-and-chrome-os/ These terms will also apply to Google translate. If you are not signed in, you won't be able to use their translation service *sigh*
There is a good alternative to Google's translation service: https://www.deepl.com/en/translator Unfortunately, DeepL currently offers machine translations for only 9 different languages but it does a pretty good job (albeit I still prefer human translations).
Are you sure? I think this only applies to translation history. The reminder at the Google Translate pages says: "Upcoming changes to history Translation history will soon only be available when you are signed in and will be centrally managed within My Activity. Past history will be cleared during this upgrade, so make sure to save translations you want to remember for ease of access later."
Google makes me dislike them more every day. I wish there was another phone alternative that wasn't Apple.