Actually, that's a myth. There is no "legal limit", only recommendations. The landlord can increase the rent by 300% if he'd like, and if the tenant accepts the increase, then it's fine. Morally wrong, perhaps, but not illegal. What is illegal is the pressure, and the false information provided by many landlords who are not following the right process.
However, as a tenant, you have a right to refuse the increase if you feel it's not a fair increase, and negotiate with your landlord. If both parties cannot agree to on an acceptable increase, then the TAL gets involved.

Now, in regards to the 2.3%, that is the suggested increase in 2023 for an unheated apartment that had no major work. But that amount does not take into account any substantial increase of property taxes, and they were substantial in some areas of the city.

Let's use the calculation grid of the TAL for the building where I live, for example. It's a triplex located in the Sud-Ouest. The ground floor is rented at $3000, and the two other apartments are rented at $1500, for a total income of $6000.

Only entering the current rent, the grid suggests an increase of 1.89%. Now, let's add the actual 2022 and 2023 property taxes. The taxes for the building, evaluated at $938,000, went up from $6076 to $6818, a 12% increase.

With these numbers in, the suggested increase is 2.76%. But that's before we take into consideration the cost of insurance.

It's a 100 years old triplex. The insurance cost went up 20%, from $2500 to $3000 a year. Entering these in the grid, now we have a suggested rent increase of 3.38%.

You can try it by yourself:
https://www.tal.gouv.qc.ca/fr/calcul-pour-la-fixation-de-loyer/outil-de-calcul