Applets are officially gone, but Java in the browser is better

> In the 2000's, politics interfered and browser vendors removed plug-in support, instead preferring their own walled gardens and restricted sandboxes

That's one way to say it. The more common way was that users got tired of crappy plugins crashing their browsers, and browser devs got tired of endless complaints from their users.

It wasn't "politics" of any sort that made browsers sandbox everything. It was the insane number of crashes, out-of-memories, pegged CPUs, and security vulnerabilities that pushed things over the edge. You can only sit through so many dozens of Adobe 0-days before it starts to grate.

For Flash vs iPhone case, it was indeed mostly politics. People were using Flash and other plugins in websites because there were no other alternative, say to add a video player or an animation. iPhone was released in 2007 and app store in 2008. iPhone and iPad did not support then popular Flash in their browsers. Web experience was limited and broken. HTML5 was first announced in 2008 but would be under development for many years. Not standardized yet and browser support was limited. Web apps were not a thing without Flash. Only alternative for the users was the App Store, the ultimate walled garden. There were native apps for everything, even for the simplest things. Flash ecosystem was the biggest competitor and threat for the App Store at that moment. Finally in 2010 Steve Jobs addressed the Flash issue and openly declared they will never support it. iPhone users stopped complaining and in 2011 Adobe stopped the development of mobile plugins.

Adobe was in a unique position to dominate the apps era, but they failed spectacularly. They could have implemented payment/monetization options for their ecosystem, to build their own walled garden. Plugins were slow but this was mostly due to hardware at the time. This changed rapidly in the following years, but without control of the hardware, they had already lost the market.