Yes. You can jump through a bunch of hoops to get a similar desktop / phone integration with Linux (or Windows) and Android using a variety of different apps...or you could just use it out-of-the-box since it's all baked in to macOS and iOS. You can tell yourself that it's 'all the same' all you want, but I've tried, and it's not the same.

I took a photo signature many years ago and have been pasting into pdfs rasterized by gimp since then.

The whole concept is kinda ridiculous, but I never would have thought that it takes a Mac and iphone to do it.

There are also privacy implications to all that integration that honestly have me a bit wary of sharing any personal information with my work Mac.

Just to pick on another, the idea that anyone would be uploading photos of their passport and drivers license is a bit crazy. That said, I could easily with Ubuntu.

Do you hear yourself? “ I paste my signature into a PDF and then rasterize with gimp”

Is any normal user going to do that? Why the hell should I have to open a image editing app to sign a PDF?!

Why has no Linux PDF viewer added signatures as an option so far?

This is why I left Linux for MacOS

Is cutting and pasting a tough one? Maybe the big word scared ya? I could have written open, with no change in meaning.

If it's not clear I didn't sign it in the technical sense, no one would know what to do with it, there's not a widely supported standard for that. These were business folks who wanted a png/jpeg image of the form with my scribble on it.

An image editor is perfect for that it turns out, and it takes two steps, three if you count save.

> using a variety of different apps

One is hardly a "variety of different apps".