That's a good point. So yes, you could argue that an award is better than 400 euro discounted business class paid fare, as the award would be more flexible. Though, covid aside, I find that generally I use points for personal travel - and that (used to ) typically not really require flexibility. But there is no denying that there is value in flexibility. How much that's worth depends on the person/situation though.

In my case I booked AMS-ATH one-way with KLM in C for 49K miles. A paid roundtrip would be 800 euros, so you could say that the 49K miles equals 400 Euros. Or you could argue that a one-way actually costs 500 Euros rather than 400. Or you could argue that a competing airline offers a, possibly better, business class product on the same route for 200 euro. It strongly depends on your view on things what the value of those miles is.