There doesn't seem to be any option that actually works1. I describe what I've explored here. After some time, my personal opinion is that this UI is a crafted dark pattern, and I don't know whether the recovery email way even works.
Is it possible to reactivate with my recovery email address only?
However if I follow the link they ask whether I've forgotten my username, my password, or other. "Other" is what applies - that leads me to this page:
I have a recovery email address set and I can't understand why cannot I use it.
If I tell the form that I don't remember my username, and enter my recovery address and a CAPTCHA, Google keeps telling me that I "may have added this [...] when [I] signed up". I guess this may have something to do with that my recovery address is also a Gmail address (was not a very wise idea, it seems, eh?).
At first I've thought that I mistyped the CAPTCHA but, after doing more than ten recognition cycles, still didn't get through. I'm sure I got the CAPTCHA right more than once.
I didn't explore all the options though. For example the first recommendation is to reset my password from a device I recently used to sign in, with options 'continue' and 'cancel'. I didn't use a device other than this computer recently to sign in so I've clicked 'cancel', I wonder what they mean by 'device' and what would happen if I clicked 'continue'.
Well, I don't really want to reset my password anyway, I just want my account re-enabled. If it takes resetting my password, I may do that. However, I can't see why should I add my phone number, when I have a recovery email set. The Help clearly suggests that a recovery email provides me enough security to recover my account. But this doesn't seem to be the case. Also the page that requests my phone number says that it needs it in order to 'immediately' restore my account, suggesting that there are perhaps ways to 'not immediately but eventually' restore my account.
What to do to recover access to my account without providing my phone number?
Is it even possible?
(1): The non-phone options are already well hidden, although they're visible enough for plausible deniability for a claim such us 'they are not providing alternate options'.
(2): I've already given my phone / address twice. You see, my phone number is not exactly a secret. On the other hand, I can't see why should I provide it when I also have a recovery email address set. I think Google demands too much and I don't like it because they don't play honest: the way they formulate their help text suggests that I can recover my account with a recovery address set.