Hundreds of trials to remove amyloid plaque in hopes for a cure have failed, yet this article discusses the prevailing bias against other theories. 

Curious to get your responses. 

https://www.statnews.com/2019/06/25/alzheimers-cabal-thwarted-progress-toward-cure/ 

We do know that amyloid and tau deformation are tied, it doesn't mean amyloid is the problem but I do think that its possible that for certain people who have the gene, with age they lose the ability to clear the excess amyloid, which seems to be the tipping point for tau tangles.

For others it could be weakened immune system that lead to the inflammation, I am pretty sure they know by now that amyloid plaque is the extinguisher that puts out the fire of inflammation in your brain  (condo/apartment )  It neutralizes viruses. But when its not washed away each night, now you've got months of extinguisher  foam blocking off the kitchen, clouding the windows, doors you can't walk around, nevermind see the exit.

Read an interesting piece about white matter damage being higher for people with sleep apnea, particularly those who don't always use their cpap machines. Apparently not sleeping at night means more brain cell death when you hit retirement age.  The culprit, too big of a tongue blocking your airway. The solution, reduce your overall level of body fat to slim your tongue, do tongue exercises or take up playing the Dirigido