What are you talking about? You're just talking about simple class manipulation which has nothing to do with actual reactivity, especially 2-way data binding.
How would you support that with your "templating engines" you keep mentioning, which to me doesn't mean anything at all, in my understanding of what a templating engine is like handlebars.
So when I click a tile you have some code on the onclick handler to go update the counter at the top? Sounds messy if there are multiple things you need to update when some data changes.
How would you support that with your "templating engines" you keep mentioning, which to me doesn't mean anything at all, in my understanding of what a templating engine is like handlebars.