Are halo products the main source of income of either of these companies, though?
Of course not; halo products never are. But NVIDIA has a halo-level revenue stream from the data centre teat, which means they're free to experiment with consumer product pricing and positioning. AMD lacks that strong, almost passive revenue input - which is why it's so completely bizarre to see them not only effectively give the mid-range away, but give it away to their competitor
that isn't even particularly interested in playing there this generation!
Every company drops the ball once in a while, but AMD didn't just drop it, they tripped over it and faceplanted. All they had to do was introduce a
moderately competent mid-range GPU series, at
moderately sane pricing, and they would've eaten the lunch of 4060 and 4070. Instead it's those GPUs that are eating AMD's lunch!
I don't think putting a huge amount of money and effort into making something that can't beat Nvidia's latest flagship is a financially sound decision.
On the one hand, it's easy to say that in hindsight; both companies develop their GPUs essentially in the dark from what the other is doing, so they can't know whether they've chosen rightly or wrongly until the other side launches theirs. You've just gotta put your head down, try to build the best, and hope it's good enough. If it isn't, then you've sunk a lot of money into being a loser, and strangely enough that isn't a compelling market position to be in.
On the other, this is again one of the reasons that it makes so much sense to compete in the mid-range first: if your product isn't as good as your competitor's, you can avoid being a loser by adjusting price. The old adage of "no bad products, only bad prices" will never cease to be true as long as we live in a capitalist world, and sometimes it's smart to take the hit to keep up market- and mindshare.
Withdraw from the battle to save your strength for the next one is not a bad plan, imo.
It's a terrible plan, because it allows your competitors to take up the slack that you've left by stepping aside. That allows them to get more of their product onto shelves, which means their brand is further into consumer consciousness while yours recedes. And when you come back to try to compete again you'll find retailers aren't willing to give you "your" shelf space back, because they've already got competitor product there that they know they can move. Nope, absolutely the worst thing any company selling consumer goods can ever do.