Google would probably love it if Android shipped with a Google-branded, end-to-end encrypted messaging app that people liked to use.
I think that there is a combination of internal Google problems and problems in Google’s relationships with Android vendors that makes this difficult. And then, any such app would be probably be in, what, 6th place at this point? Meanwhile, Meta has apps #1 and #2.
I would argue that the evidence over the past several years has shown that the default position w.r.t. to Google's motivations should not default to 'benign' under any circumstance. With all other things being equal, and without evidence to the contrary, it makes sense to operate under the assumption that Google will enthusiastically and universally do everything they can to violate your privacy in any manner available to them, no matter how subtle.
“Not benign” and “not malicious” can both be true. Google is motivated by self-interest, is staffed by engineers which have various conflicting self-interest and ideologies, and has a culture with various competencies and dysfunctions. Sometimes Google will do things that benefit consumers and sometimes Google will do things that harm consumers, but it’s not out of altruism nor is it out of malice.
Same as other large companies.