Yes, you can use WhatsApp, Facebook, Instagram, and TikTok with an eSIM.
An eSIM is just an electronic version of a physical SIM card, and it does not affect the functionality of your phone or its apps. As long as your phone is compatible with these apps, you can use them with an eSIM just like you would with a physical SIM card.
When you activate an eSIM, your phone number remains the same, and all of your existing apps and data remain unchanged. Therefore, you can use all of your apps, including WhatsApp, Facebook, Instagram, and TikTok, as you normally would. However, you may need to ensure that your phone is connected to the internet, either through cellular data or Wi-Fi in order to use these apps.