LWC RecordTypeInfos via getObjectInfo Unable to access

After trying to replicate your issue (which I was able to), it turned out that your issue is on this import line:

import { getRecord, getFieldValue, getObjectInfo } from 'lightning/uiRecordApi';

You have the wrong adapter here lightning/uiRecordApi for getObjectInfo resulting in all the issue where objectInfo never gets populated thus returning that error.

---

To fix this, getObjectInfo needs to be imported from lightning/uiObjectInfoApi as below:

import { getObjectInfo } from 'lightning/uiObjectInfoApi';

I used the example in this documentation as a reference while trying to identify the resolution.