Personally my main motivation is I don't want anyone to snoop what sites I visit and then sell that data, my ISP included, but there are other issues too. To quote Cloudflare [0]:
> Queries could be directed to a resolver that performs DNS hijacking. For example, in the UK, Virgin Media and BT return a fake response for domains that do not exist, redirecting users to a search page. This redirection is possible because the computer/phone blindly trusts the DNS resolver that was advertised using DHCP by the ISP-provided gateway router.