Those coffee filters are standard in Japan which is where I discovered them.
Instead of intant coffee, prefilled ones were in all my hotel rooms in Japan. A kettle is standard in rooms as is green tea.
I'm sipping a cup of coffee made with one of those filters as I write this.
If I want to make filtered coffee in a room without a kettle....I boil water with my immersion heater in the Lifeventure cup. Pour it into the silicone cup. Set up the filter with coffee in the Lifeventure cup and pour the water from the silicone cup over the coffee filter into the Lifeventure cup. Much nicer to drink from than the silicone one.
All of that takes up less room and weighs less than the travel kettle.