Spent some time trying to debug why absolute links on Netlify aren’t generated. As it turned out, if you have baseURL = "" inside config.toml, then you also need to have these lines inside netlify.toml:
[build]
publish = "public"
command = "hugo -b $URL"
Without -b $URL it just doesn’t work, although I have command = "hugo -b $DEPLOY_PRIME_URL" as recommended in this thread.