The main issue with ARC seems to be driver support in specific games, DX11 being particularly problematic.

Intel basically have to catch up on the ~10-20 years of kludges that AMD, Nvidia, and game devs had already implemented when the games were released.

They've been making strong improvements to their drivers though.

Their iGPU is great for home media servers. Low power draw, QuickSync can handle multiple 4k transcodes, and one less part to buy.

iGPUs still aren't a great choice for gaming on desktops, even the latest AMD APUs perform poorly in comparison to the cheaper dGPUs.