When daddy comes for Canada and you attempt to fly your fabulous F-35 for defence and then get hit with a "Please enter daddy's password to take off", you will understand that gripens that can actually fly and fight for you are infinitely better than F-35s
You really think that would make a difference when USA invades Canada? A few J-39 against USAF?
I am sorry, no.
In that situation, there is no practical difference whichever plane to have but in the case where Trump drops dead or whatever, having F-35 gives a longer competitiveness in the future. The CF-188 is 44 years old now, to put in perspective, if we get a new fighter today, the next fighter we get would be 2070.
Canada should get a European 4.5gen as a stopgap (possibly 2nd hand) and buy into GCAP.
Must as well skip 4.5 gen and get GCAP which I would be fine.
Mixed fleet (F-35 - Gripen - Erieye) is arguably the best bang for buck fleet Canada can hope to get. There's simply no point going for other western fighters, nor throwing additional money into air in general, USAF is always going to be dominant.
Additional lightnings don't add nearly as much value as the already contracted ones, and full lightning fleet only made sense in a world which Canada itself proclaimed as gone. I.e. it was in essence paying symbolic feudal homage for a right to be another civilized one man on the right side.
What they caaan do is start producing IADS. In Canadian case, pretty much from scratch, as they have nothing.
Which indeed reinforces American point of free riding.
Whatever military hardware we get can't stop USA invasion from the south, put UK/germany/France in Canada's geopgraphy, it would still be a stomp. All our major cities are next to the American border. Once the cities are taken, canada will sadly cease to be, all the guerrilla war talk are nonsensical, pure copium. Despite the huge geography, most of us canadians won't survive in the country side during winter. Winter will eat us alive. The american force could leave the country side to rot.
The F-35 is the only plane on the market to give us the longest competitiveness in the future if the US invasion never happens, it would be used in expeditionary matters and keep russians away from the north (though even if Ukraine war never happened, i doubt they are dumb enough to go invade through the Arctic. I've been there)
Having both J-39 and F-35 is an option but politically, it seems to be an either or situation.