It's more about DPI than the number of pixels ("resolution"). In more exact terms, the angular diameter of single pixel, or the ratio between DPI and viewing distance.
The resolution is good enough when you cannot anymore see any pixelization effect from typical viewing distances. 1920x1080 on 15" screen is not quite enough, 2560x1440 or 2880x1800 are better options.
I'm not sure what's the status of high-DPI support in FOSS graphics stacks today. The 1920x1080 may be practical choice, because it makes UI elements to look "normal size" on 15" screen without additional scaling. Without high-dpi mode, e.g. websites look way too tiny past 1080P (1 virtual pixel == 1 real pixel).
The resolution is good enough when you cannot anymore see any pixelization effect from typical viewing distances. 1920x1080 on 15" screen is not quite enough, 2560x1440 or 2880x1800 are better options.
I'm not sure what's the status of high-DPI support in FOSS graphics stacks today. The 1920x1080 may be practical choice, because it makes UI elements to look "normal size" on 15" screen without additional scaling. Without high-dpi mode, e.g. websites look way too tiny past 1080P (1 virtual pixel == 1 real pixel).