@sitta_europea
Read the article again. It is encrypting not the DNS lookups from your browser, but the lookups from a stub resolver like the one your wireless router likely has to a full fledged DNS server like the one your ISP likely has. Since your stub resolver caches things you've looked up recently, the traffic to your ISP's resolver is a lot smaller and it can absorb the additional traffic from using encryption. DNS servers are hardly bandwidth bound (barring amplification attacks)
Since the UDP packet size for DNS is limited, due to all the additional stuff getting crammed into DNS these days it is more and more common to use TCP anyway.
