I'm still using Maptools (
https://www.rptools.net/) for GURPS. It's free, open-source, fully customisable, supports drag-and-drop of images and even has limited GURPS frameworks made by users. It also does fancy stuff like vision-blocking, sight-ranges etc. out of the box and has decent tutorials for that.
On the negative side, the interface looks its age (though the programme is continuously updated) and once in a blue moon some player has some java problems that mean the programme can't run properly on their computer (one player out of about twenty in the last four years in my case). You don't get to backup all your stuff to some online platform, of course, but depending on your views that might be preferable. You can use your own server if you want.