What you are describing is not an alaska airlines specific issue. Every single US-based airline has the same process - all the low cost half-price miles seat are taken about 1 year out.
So what you are seeing and what the agent told you is completely normal.
Think about it as a ticket to a popular play (like Hamilton) or very hard to get restaurant or limited availability black friday sales as you said. Everyone knows what the deal is there and this is why they line up at 3am. Same over here. The airlines release a few low-price award seats, and people do buy them up right when they release, so you need to "line up" one year out otherwise just post angrily on the internet.
For reference, I booked such tickets on the dot at midnight when they released 1 year out. After a few hours, low price tickets for that flight were gone and only the higher price remained.
Again - this is not an alaska airlines specific issue. There are 300 million people in America, and many know about a highly sought after low price ticket to hawaii releasing one year out. You don't think it will be taken up?
If you want to take advantage of the better pricing, start booking your award travels 1 year out like many other people on this forum.