I think you’ve put your finger on one of the primary issues still remaining for non-Roman catholics, interested in walking together with Rome.
While the charism of infallibility is only officially assigned to the pope in particular instances, and to ecumenical councils, the expectation of submission to the local bishop (or the pope) is a daily kind of thing. So, while the catechism is not technically infallible, from a lay perspective, it is binding, just like any other utterance of the Church. For example, those Anglicans who have accepted the offer of Rome to come over en masse, have signed their subscription to the CCC in formal sessions.
So, for most of us outside the communion of Rome, we’re not willing to bow to whatever Rome may or may not teache next, even if we agree with what she is teaching today. Once the councilliar tradition died in the west, the proclivities of whatever pontiff ascended St. Peter’s chair became de facto binding on every Roman Christian. There is no authentic appeal process to what an individual conscience may discern to be error in a teaching of Rome (for example, the CCC) since submission is the rule. What seems to emerge are cloaked factions, all contriving for control, seeking to get their own pope on the throne.
If I recall, this was fundamentally C.S. Lewis’ response for why he never joined the RCC. He was in agreement with much, if not all the doctrines promulgated by Rome in his time, but he could not promise that he would be in agreement with whatever they came up with next, be it catechism or otherwise. Such is the case for many of us, who are willing only to submit to the Scriptures, and those men who have themselves submitted to them.
Grace and peace.