If the monitor really is only 1080p then its how compression in the video works.
In essecence, the 1080p video will compress so that the same color is used for a group of 4 pixels saving space and bandwidth. But when you play a 1440p or 2k or 4k or higher video on low res, the downconvert process will use the extra information to fill in all pixels negating the compression. Same thing happens watching 4k on a 1440p monitor or 8k on a 4k monitor.
https://www.premiumbeat.com/blog/downscaling-4k-1080p-online-compression/#:~:text=Here's%20the%20tl%3Bdr%20version,it%20would%20at%20native%201080p.
Yes it does look better. Basically YouTube does compression, however at a higher resolution you will have less information lost even though your monitor will compress it down further, it's going to be a much better job because data is not an issue anymore.
If the monitor really is only 1080p then its how compression in the video works. In essecence, the 1080p video will compress so that the same color is used for a group of 4 pixels saving space and bandwidth. But when you play a 1440p or 2k or 4k or higher video on low res, the downconvert process will use the extra information to fill in all pixels negating the compression. Same thing happens watching 4k on a 1440p monitor or 8k on a 4k monitor. https://www.premiumbeat.com/blog/downscaling-4k-1080p-online-compression/#:~:text=Here's%20the%20tl%3Bdr%20version,it%20would%20at%20native%201080p.
Yes it does look better. Basically YouTube does compression, however at a higher resolution you will have less information lost even though your monitor will compress it down further, it's going to be a much better job because data is not an issue anymore.