I never had an issue with a GTX 1660 Ti on Arch. It’s been 5 years.

Older cards (in my case, the 970 M iirc) are slightly more annoying because Nvidia doesn’t support them anymore. So you can’t just install the generic, up to date, Nvidia driver package. You have to use Nvidia’s website to find the latest driver that supported them, and then install that one through your distro’s package manager.

Afaik, Nvidia supports all cards from the 16xx series upwards in their driver, as of right now.