You can’t hit what you cannot see.
The F-35’s radar and EOTS make it so it sees anything less stealthy than itself first.
If you can see first and shoot first, you win the BVR fight. Full stop.
Not that this matters since if F-35s and grippens are shooting one another, the western world has ended as we know it.
Either way, Canada needs a homeland defense fighter, not a “join in and be part of coalitions that fight away from its shores” fighter.
The downside of not having the F-35 is mostly in not being able to effectively fly the same 5th generation tactics, and be part of the same deployments as the countries using them.
In Canada’s case, I don’t see them forming an armed coalition with the US so… not much lost.