I feel that this reflects very poorly on the competency of IRCC. If they say that "it’s not possible to apply for citizenship online without a direct invitation at the moment", then we have to take it at face value. Communication from a government agency must be clear, precise, and unambiguous. IRCC speaks of a "direct invitation" or a "random selection" process but does not explain how this works. It is extremely confusing.
If they said that all eligible applicants must register their interest in submitting an online application, but that only a fixed number are picked (for example on a weekly basis) to proceed to the online mode (the rest have to submit on paper), or something like that, THEN I would understand.
Without any further explanation, the statement regarding a "direct invitation" is confusing.