

False. Samsung’s own troubleshooting page for the OLED G9 tells you to go to Menu > System > DisplayPort Ver. > 1.2 or 1.1, then reconnect the cable when the host doesn’t negotiate DP 1.4 cleanly. Users on the Neo G9 report the same OSD option, having dropped the DP setting to 1.2 and 1.1 (OSD) while troubleshooting a no-signal problem. Dropping the version is a standard troubleshooting step. At 1.2 the monitor stops requiring DSC and HBR3, so if link training is the problem the port will often show up as connected even though 240Hz won’t be available.
And nvidia_drm.modeset is a kernel bool parameter, and sysfs renders bools as Y or N.

https://www.samsung.com/tw/support/computing/about-49-inch-odyssey-oled-g9-display-troubleshooting (OLED G9)
Under the no-picture item it says to check whether the PC supports standard DP 1.4, and if it doesn’t, to set Menu > System > DisplayPort Ver. to 1.2 or 1.1 and reconnect the cable. The menus are probably different between the Neo and OLED models.
Your ‘-1’ comes from the Intel driver, where modeset is an integer and -1 means the driver default. OP has an RTX 5070 Ti, and ‘nvidia_drm’ modeset is a boolean, so ‘/sys/module/nvidia_drm/parameters/modeset’ reads ‘Y’ or ‘N’. Files under ‘/sys/module/*/parameters’ show the value the loaded module is running with.