Agreed - I'm personally a bit sceptical at the estimates saying it'll be the end of the decade for a mature quantum computer to be built, much less in 20 years' time. But I am convinced that it will happen, and given the long shelf-life of some of the data that's being encrypted now, and its vulnerability to HNDL attacks, I think the argument for coming up with durable post-quantum encryption algos now is actually quite prudent.