yes especially if i am using another securing DNS such as Adgaurd which have all this option or just it is online DNSYes, it forces Windows to resolve DNS by using Avast servers.
For advanced users like most of people on this forum, this feature it isnt that important because they know how to change DNS, to use DNSCrypt and so on, but for the average joe it is a nice security feature to avoid DNS spoofing and similar tactics.