Yes, ISPs can know IP addresses and map domains to IP addresses, they can also know exact SNI names, all kinds of passive TCP-level information about your commu

Yes, ISPs can know IP addresses and map domains to IP addresses, they can also know exact SNI names, all kinds of passive TCP-level information about your communications, can do active probing for all kinds of information on behalf of you, can use all that together to build a much more detailed profile of you, than available through DNS queries. There is an entire industry of commercial DPI solutions to do that. On top of that ISPs can always block DoH and force fallback to their own DNS servers. So, a minimum amount of privacy can only be achieved with a VPN (or a proxy), not DoH, DoH just leaks to and centralizes data on third parties, violating privacy, making it easier for state actors to spy on people, things like that, it might even give governments capabilities to do world wide censorship if all major browsers implement it. Mozilla, Cloudflare and everyone else involved are being very dishonest when it comes to DoH.