AFAIK, STTNG has one other advantage. They used real models and DS9 mostly switched to CGI. Old CGI is harder to beautify than models.
"They’re using the original Lightwave scene files for camera and model movement, lights, etc. It’s also the original 3D models and textures used on the show – and nothing has been updated in any way other than being rendered out at 1920x1080. It’s the raw CGI without any post work."
In DS9 / Voyager as I understand it, they transitioned from using models to directly generating the whole shot with CGI at NTSC resolution. See https://memory-alpha.fandom.com/wiki/CGI#Acceptance
This means that in TNG they just had to recomposite the film with a newly created high-res phaser shot; whereas for DS9/Voyager they would have to recreate the whole shot in high-res CGI.