Sending files to someone else is a problem with a ton of solutions, some of them better than others, but none of them actually solving the problem. Email often has size limits and spam filters block certain attachments. Dropbox is often restricted at most workplaces, and not everyone uses it. It also has size restrictions. USB is the most reliable, but then you get into the whole "it's NTFS formatted which doesn't work on my Linux machine" or it's HFS and I need to use it on Windows" nonsense, plus sending it longer distances takes days through the mail.
But converting documents... guys it's just electricity running through fancy sand. It shouldn't be that hard. I work on software where I'm often connected to a jump server without Office installed on it, and the software expects me to open a spreadsheet for troubleshooting. I was doing some audio recording recently and the hoops I had to jump through to save it as MP3 weren't insurmountable, but still pretty annoying.
And don't get me started on the Office 2003 spreadsheet that makes me boot up my Windows XP VM to open because the macros won't work on Office 2017. Or when I need to use Visio but there's no Mac version so I have to open my VM too.
And the web just makes it worse... no more software incompatibilities because when software isn't supported anymore, we just shut the servers down and everything is gone forever.