Your eSIM can technically be left in your device indefinitely without any adverse or negative consequences.
This will allow you to topup the same eSIM with a new Data / Voice plan even years from now, which will allow you to access Data and Voice plans at much better rates and is generally more economical / cost effective.
In addition, you will not need to go through the activation process again, as you will already have a confirmed working eSIM installed on your device.