See my response above - you only get a limited number of uses of an existing phone number as verification with Gmail. That number is said to be between 4 and 6 different email accounts, although Google doesn’t seem to communicate the actual number. The counter isn’t reset just because you might have deleted a previous account which used the same phone number for verification. Google does this to prevent people from abusing its own systems, e.g. by trying to create 15 email accounts with the same phone number for verification.
Apparently, the only way around this limitation is to use a different phone number.
That’s interesting, because it hasn’t happened to me. I have had getting on for a dozen gmail accounts and use the same number for each. At the moment, I have 7 or 8 active gmail accounts.
There’s also the gmail feature that lets you use existing gmail addy as a new one by inserting a new dot(s) where you like - new to most other places but still directs to the same mailbox. Depending on why you were thinking you needed a new address this may be quite sufficient for some purposes.
It has happened to me on one of my phones, I had to switch to a different SIM/phone number in order to set up the account.
Even today, I can’t set up a 2nd business Gmail account on one of my phones because the number is already associated with a 1st business Gmail account. Even the admin page under Account Admin in Google Workspace, where these things are usually configured, is of no use to me.
Not me, I refuse to speak to any computer (Siri, Alexa, Doris the Talking Frog), with the possible exception of the one on the starship Enterprise as otherwise you can’t work the lifts.
We use Alexa and have Apple speakers that talk to us every now and then. I don’t think Siri is too good but Alexa is. Both of them are in my car and some BMW voice recognition software. I have them all turned off but maybe I’m being a bit of a luddite. The R5e has some Google and some Renault voice recognition, but we don’t use those either.
Google tells me her name is Estelle Skornik. sadly no phone number listed. 
