We’re all spending a lot of time using Zoom. Yes it’s had security issues, but pretty much any software out there will have.
So how about some images that are in the “public domain”? These are images where either the copyright has lapsed or they’ve been made available under a liberal license. You can find images that are under a Creative Commons license here, for example.
Just remember to edit or resize the images so that they work well. They’ll need to be in 16:9 aspect ratio and at least 1280 by 720 pixels resolution.
If you don’t feel up to creating your own there’s plenty out there already including this rather quirky one of a crowd of people:
There’s several more that you can choose from here.