Yes, your GPU needs to support the newest DisplayPort 1.4 standard (with updated DSC) for 4k@144Hz. AFAIK all Nvidia 20xx series cards and Radeon RX 6xxx cards

Yes, your GPU needs to support the newest DisplayPort 1.4 standard (with updated DSC) for 4k@144Hz. AFAIK all Nvidia 20xx series cards and Radeon RX 6xxx cards support that. The fallback is 4k@120Hz which should work with older cards, but when testing with my GTX 1070 I had to add a custom resolution to get that set. With my new RX 6900 XT there are no problems.