Paying for sync is my way of supporting the developers of this excellent application. The sync works well, it's less hassle, and more secure than using the usual cloud services, particularly for iOS and Android. Obsidian and Tailscale are the two pieces of software I gladly pay for, I don't ever want them enshittified!
Now imagine that instead of an iPad, you've just bought a new house with fantastic materials and an integrated software system. Should the company that built it have the right to control how and who interacts with your house?
Not sure that is strictly correct. I vaguely remember a command line browser early in the piece. The inline image ability and <img> tag came a bit later in the story when Andreessen put it into the NCSA's Mosaic browser. I've always wondered if it was that single thing that really made the web take off, more so than hyperlinking which had been around for quite a while. People like pretty pictures, especially advertisers.