Sure, there’s nothing wrong with fantasy races with little to no resemblance to humans. Dragonborn are a good example of this. But a lot of the staple fantasy races - elves, dwarves, halflings, gnomes, etc. do look very human, and are therefore likely to have ethnically-coded features, even if the artist doesn’t consciously design them that way. You can avoid the most obvious features like skin tone easily enough, but there are other things, like facial proportions for example, that can unintentionally suggest an ethnicity. And in a world where whiteness is treated as the default, artists often end up unconsciously coding characters white if they aren’t consciously trying to code them nonwhite.
Furthermore, even in a hypothetical fantasy world where no races resembled humans - a setting populated entirely by dragonborn, warforged, thri-kreen, and other races typically considered “too weird” by the same people who complain of elves and dwarves being too human - would that be better? I don’t know. It feels to me like if there’s a problem of POC not being able to find characters that look like them, making sure white folks can’t find characters that look like them either is a worse solution than adding characters that look like POC.