While I generally agree, the project needs to be big enough that somebody looks through the code.
I would argue Microsoft word is safer than some l small abandoned open source software from some Russian developer
That's true, but I'm not a programmer and on a GitHub project with 3 stars I can't count on someone else doing it. (Of course this argument doesnt apply to big projects like libre office) With Microsoft I can at least trust that they will be in trouble or at least get bad press when doing something malicious.
Ehmm. if nobody uses it, it kinda doen't matter if it's safe. And for this example: I bet more people had a look at the code of LibreOffice than MS Office. And i dont think it sends telemetry home in default settings.