I can't imagine going on a trip without an inverter. I'm surprised to hear some of you guys who have a one rarely uses it.
Some of our little mains power gadgets that we like to take with us would depend on having a functioning inverter. Cameras, camcorders, laptops, etc etc. It's true many little gadgets like mobile phones, tablets now come with 12V to 5V USB charging adapters. But, many other gadgets still depend on having access to mains power. I use one modified sine wave one and a one true sine wave one. There're higher wattage low frequency ones that are good with high power demanding appliances, but they are usually dearer.