I can't comment on all of Chrome's behavior here, but Firefox ignores autocomplete="off" too, and this is noted on MDN [0]. This is because a lot of poorly-managed sites think they're being security-conscious by disabling password managers, so browsers had to step in and ignore the attribute.
I don't have a problem with any browser supplying credentials that the user has already used and chosen to save for a specific particular domain/form/input.
The issue is that Chrome is randomly/unpreventably suggesting all sorts of data even when field is for a medical patient's name rather than doctor using it, or when it's a generic chat-message field, and it does all that when the user has never used the form or even visited the domain before.
Informing all customers that it's out of our hands and can only be stopped by disabling their personal Chrome settings is... Not practical.
[0] https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes...