I have many nerdy friends who have been Linux users for ages. But most of them don’t know such a thing as Openwrt exists or have never bothered to give it a try. It’s a very fun piece of software to play with and can be extremely useful for routing traffic. Wondering why it isn’t more popular/widely used.
It is still much more secure than to stop using it and let your other devices go naked.
Not necessarily. I would at least keep your eye out for something newer.