It depends on different factors (screen size and thus pixel density, personal preference and eyesight) but this is my subjective opinion that the VM is OK to look at (i.e. text is readable and not too small).
Host: Ubuntu 18.04 host, VMware Workstation Pro 15.5.7, on 27" 3840x2160 monitor
Guest: Windows 10 20H2 VM at 2880x1800 (16:10 aspect ratio) at 125% scaling in single window, same VM at 3840x2160 (full screen mode) at 125% scaling
Host: macOS 10.15.7, VMware Fusion 11.5.7 on 16" MacBook Pro
Guest: Windows 10 20H2 VM at 3840x2160 at 150% scaling in single window, same VM at 4096x2560 at 150% scaling (full screen mode)
The scaling refers to the Windows 10 OS display scaling settings.