I find it hard to put much stock in studies like these, simply because as stated in the study, the symptom of long COVID observed is "most commonly fatigue (70.6%)". How can we be sure that this fatigue is not due to going through a pandemic situation? Well, they do address this later:

"This figure is substantially higher than the prevalence reported from a review of Australian data from earlier in the pandemic which found 5% to 9.7% of persons with SARS-CoV-2 experienced ‘post COVID condition’ at 12 weeks or more after infection."

So that somewhat accounts for it, although NOT completely, because later studies are more closely synchronized with more return-to-work initiatives, which means (A) more people in the office compared to earlier studies, and (B) more people on the roads. The greater contrast between earlier studies and these ones with respect to these environmental conditions could also have accounted for this higher prevalence of long COVID.

(I'm NOT saying that there is NO such thing as long COVID, only that the effect sizes MIGHT be misleading.)