The problem is that it doesn't. Software developers get the latest hardware, either because they like it ("it's my job") or because their company pays for it. As a result, they write software that works on their hardware, which is obviously more forgiving in terms of performance. Eventually, everybody has to update their hardware because their current hardware can't load a simple website or a chat app.
I can see a huge difference when loading website on my work computer vs my personal computer. Just last month my weather forecast app was updated and became literally unusable on my phone. Of course I can't use the old one anymore, so I don't have access to the public national weather forecast app. It works great on more modern phones though... showing exactly the same data as the previous app, but... I guess it looks more modern?