Adam Kos The so-called eSIM replaces the need for a physical SIM card. It's basically just a small chip inside your device and works in a similar way to the NFC chip used for payment technologies like Apple Pay and Google Pay. But it's not an eSIM like an eSIM.
Apple first started supporting eSIM in iPhones with the iPhone XS and XR in 2018. Of course, they are also part of the Cellular versions of the Apple Watch. The fact that this is a clear trend is evidenced by the growing popularity of this standard, support from operators and the fact that iPhone 14s are already distributed in the US without a physical slot for a classic physical SIM card.
In the country, iPhones 14 still have a SIM slot
In phones, eSIM actually behaves the same as a classic SIM. However, its advantages also exist when traveling, when you can use the eSIM of an operator operating in a given country, for example, for a data package without the need to visit kiosks. But there is also one disadvantage. The catch is, of course, that you cannot remove the eSIM from your phone and insert it into another phone.
It could be interest you
Vratislav Holub Apple Watch issues
But if the eSIM in the phone behaves like a separate SIM, in the Apple Watch it does not. It is not possible to have a unique phone number in the Apple Watch and use it completely independently of the iPhone. Even if they contain an eSIM, it is a copy of the phone's SIM card. This means that when someone sends you a message or calls your number, that information will appear on both your iPhone and Apple Watch, whether they're in range of each other or not. But if you had a unique number in your Apple Watch, the information about the call or message would only come to them. It would therefore be a sovereign device, which the Apple Watch is not.
Apple Watch Ultra is only available in Cellular version
It is in this copying technology that the biggest problem lies. If it was a unique eSIM, the Apple Watch would behave practically the same as any other device with a SIM card. But that's not their purpose, because they're still just an extension of the iPhone. That is why it took such a long time to introduce this Apple technology into the network of operators in the country, when it is still supported by only two, namely T-Mobile and recently O2. Vodafone is the last operator that does not yet support eSIM in the Apple Watch.
In my opinion, esim does not work optimally on the Apple watch. I called T-Mobile and they told me that it's not an esim problem, but a communication problem between iPhone and Apple watch. Sometimes it happens that the iPhone simply rings and the Apple watch does not, other times you receive a call on the Apple watch and hear nothing and so on, so there is really no 100% reliance on the Apple Watch... that's a big shame. I really don't know how exactly esim works on the Apple watch and how the communication between the iPhone and the Apple watch takes place via the telephone operator.