I see the value of redemption as actually increasing with my limited experience. I "happened" to book at the right time about a month ago for a March stay. I booked 7 nights at St Regis in Singapore and it required 266K Bonvoy points. I was able to add points to my two 35K certificate when reserving and it took only 196K Bonvoy points from my account. It has since gone up to about 350K to redeem for the room during the same period but I am not using this new point requirement. It costs about USD3,350 for cash stay.
My cost was $95+$95 (for the 2 credit cards membership) + 196K Bonvoy points, which results in about 1.7 per point value. for the 196K Bonvoy points.
If I use Points Guy's valuation of .007 cents, I am looking at my cost of $190+$1,372 = $1,562 to book a $3,350 stay. I get their famous breakfast thrown in for free because I am Titanium elite. That's really good redemption value.