But that's not what the terms on both Google/Meta and Deepseek say.

There's no term in their ToS saying Google/Meta restricts the data collection to forms, which means that if the ToS allowed them to collect them from forms (and as you admitted, we do know for a fact that they do), then it also allows them to collect it outside of forms. The reason I put the search suggestions as example is because it's one we CAN know (and thank you for agreeing on that), but that doesn't mean they don't do other captures at times we DON'T know... and also it's not the only place, Google owns several captcha mechanisms and capturing input patterns is common on those too (and captchas capture outside forms too!). Another obvious example is Google docs, another is Google translate... and again, those are only the obvious ones, we don't know if there are non-obvious ones.

In the other direction too, Deepseek terms don't say it does it outside of forms either. You are jumping into assumptions by saying it acts the same as a traditional keylogger and that the keystrokes are captured for "anything typed". For all we know the only place they might be capturing is when the user is in very specific steps of the login process, maybe for captcha purposes too, or specific forms for preloading results, etc. There's no reason you should trust they do it any less/more than Google/Meta does, the ToS in both have the same lack of information in that respect.

You can only make assumptions one way or the other, since the terms are not specific on what exactly they allow themselves to do, in the case of Google/Meta they're so sneaky that they avoid saying they do capture them (even though they do, as you yourself admitted), while in the case of Deepseek, even though they are a bit more specific by using the word "keystrokes", they also don't specify where/when/why (other than "to give you a seamless log-in experience and for security purposes" ..but that's also unclear wording).