@medz solid pass on coffee. Also the tea was for the wife and when I filled the pot using the spout I was told I was doing it wrong. My thought is that the goal was to get water into kettle and either hole would work.
Mostly I use the kettle to make coffee in a 1.5 liter French press: I fill the press and pour the water into the kettle, which is much faster and easier via the top.
I always use “fresh” water in the kettle and only heat the amount I need so after the water boils and I’ve poured it all out, I remove the top and leave it sideways in the hole so the kettle can dry out to avoid rust. This also makes filling it easier the next time, since the top is already open.
When I make tea, I make it by the cup, or mug. I use a kettle which I fill through the spout to heat the water.
Looking at images of teapots, if I were to use one, I would probably use the big hole to fill it. I would have to open it to put the tea in anyway.
/giphy teapot short Stout
I need a picture of your teapot to make an educated response. Because on my teapots, the spouts are very narrow. It would never have occurred to me to try to fill them through the narrow spout when there’s a larger, much easier to use hole on the top expressly designed for the purpose.
I could fill the electric kettle through the “spout” but I usually just open the top and put enough water in to make a couple cups. Because I will turn it back on through the day to make another cup. I’m just heating water to use in my cup with a teabag or make coffee with the aeropress though. Not making an actual pot of tea.