This is click bait verging on vaccine minsinformation.
The headline could be: "4 doses may not more effective at reducing Omicron infections than 3 doses, but 3 doses is actually very good at preventing infection, hospitalization and death from all known variants - and even 2 doses - while not providing a lot of protection against Omicron infection ... does actually provide good protection against infection from other variants but also hospitalization and death from all variants, including Omicron."
1) 3 doses are actually fairly effective at stopping Omicron infections, at least for 12 weeks - we can see this definitively in data from around the world.
They indirectly mention this in the article.
Ontario data [1]
In the first graph, you see COVID 'cases' increase with the onset of Omicron, even among those with 2 doses - clearly 2 doses are less effective at preventing Omicron cases - but still pretty good at stopping Hospitalization and Death. Later in the time series, precisely when people started getting their boosters, you see a rapid increase in levels of protection against infection, hospitalization and death.
2) The vaccines by all accounts still seem to be effective at preventing cases (and hospitalizations and death) of previous, more deadly variants.
3) The difference between 4 and 3 doses is noteworthy, but it's definitely misleading to indicate 'ineffective when the baseline of comparison, i.e. 3 doses, is actually 'effective'.
4) As we can see from the Ontario - even 2 doses - but certainly 3 doses - are very effective in reducing hospitalization rates and death.
(From that data 'minimum 2 doses' reduces Hospitalization by 5x and death by 20x. That is mixed data from 2 and 3 doses, given the ratio of those having 3rd dose, we can estimate that 3 doses is even considerably more effective than those numbers).
Given the inconsistency between the headline, their own stated information, and easily available data from various legitimate authorities - I suggest that this article, at least the headline, constitutes purposeful misinformation.
[1] https://covid19-sciencetable.ca/ontario-dashboard/