[0] https://www.minimalcompany.com/
[1] https://www.thelightphone.com/lightiii
Email clients need an HTML renderer, and email users generally want links in emails to work, so email without a web browser seems unlikely.
Lastly, you could use a phone with Sailfish OS or the like, where presumably you can freely add and remove anything you want.
I know Screen Time on iOS allows to do this, and remember reading about people specifically doing this on their iPads to transform them into 21st century typewriters, only white listing their favorite writing app.