DoH means that each application does its own DNS queries, instead of using the OS's functionality. Whether that includes reading /etc/hosts is up to the application, and it looks like high profile applications like Chrome and Firefox don't read /etc/hosts.
> The entire point of these technologies is to prevent your ISP and everyone else along the way from knowing which websites you visit.
More correctly, the point is to shift all that from one organization to another. Maybe you trust Google or Mozilla more than you trust your ISP, but I don't think it's the same for everyone.
You could even argue that your ISP can already see which hosts you connect to, so using it's DNS resolvers doesn't add much information for them. Using DoH means that both your ISP and another party can see that.