Can we use only eSIMs without inserting any physical sim?

No, Apple does not make an international iPhone. Some markets require that a physical SIM slot be available. Other markets, such as US have no such requirement and iPhones have dual eSIM only. It’s a best practice in most cases to purchase an iPhone intended for your specific market and individual requirements.

It would depend on your location and the model phone you have. In the US, the iPhone 14 you show in your profile only has eSIMs. Phones in some foreign markets still have a SIM slot.

It also depends on the carrier. Not all carriers in all countries support eSIM.

Good point!