More work for less of a meaningful impact as an addition to the game. Not really sure the point you're trying to make? Of course a new race requires more art asset development especially at a point when a lot of art assets are needed (new zones, new dungeons, new armor and weapons, new primals, new enemies etc.)

It doesn't change the fact that compared to new jobs, new races are far less important additions to the game. It's why they're saying they're likely done adding new races, while introducing the limited job system to add additional jobs to the game.