If you use a very secure password (letters, numbers, symbols) on your gmail account you do not need the double verification that involves the use of your mobile phone.
Example of secure password: Using the first line of the song: We are the champions my friend...
Take the first two letters of every word with some capital letters: WeArThChMyFr
To make it better change some letters by numbers and symbols: W34r7h(hMyFr and it is done!!!
More information about how to create a strong and easy to remember password and remember it... here
This link leads you to an article that explains how to avoid the use of the mobile
This video explains how to open the google account wihout giving your telephone number:
This link leads you to the "Oficina de Seguridad del Internauta" OSI that depends of the Spanish Govern and explains everything in Spanish. There you can find the advantages and desadvantages of having your mobile phone linked with your gmail account 👉 here