I only redeem for high CPP, and find that I usually get around what the sites I’ve seen suggest. I don’t read card reviews, but while searching for good redemptions, I do see their estimates.
There are places and things I’ll do every year, some of which are good redemptions, others I pay normally instead and store the points for later. Then there are things I’ll do simply because they are good redemptions, and allows me to try things I might not think about otherwise. This is a good balance and leaves me with a ton of points in cases of emergencies.
There’s some level of inefficiency because points are devalued and sitting on hundreds of thousands of them can lead to value lost. At some level though, it’s too much to think about, so I just accept that.