Your last point is probably true for domestic missions. However, Canada has also deployed the CF-18s in missions abroad, most recently (?) against ISIS in Iraq and Syria.
The CF-18s were also deployed in Yougoslavia and Serbia IIRC.
For the very basic and extremely infrequent strike missions that they are used for, the CF-18s and the F-18s we got from Australia will realistically be enough.
The problem with the Australian ones is that they're old and worn out, so they're very expensive and unreliable to operate. Those planes are approaching their fatigue limits, and they're not going to become more reliable.
Yes that's true, but the F35 is not exactly cheap to maintain either at 42 000$ per flight hour and the air-frames themselves are basically free and can be cannibalized.
