In what way is open source Android a lie? I never used any other version, I do not have a Google account, nor do I have any Google-proprietary software on my devices yet they still run all software - including the Swedish "BankID" electronic ID app which is needed for just about any interaction with anything official nowadays. That "BankID" is, together with Firefox Preview, the only software which I got from the play store repository (using "Aurora Store", an alternative play store front end hosted on FDroid), the rest is all free software.
Of course that means I do not use things like Facebook, Twitter, TikTok, Whatsapp, Snapchat, Instagram, Skype, Zoom, Google Maps etc. I have replacements for the useful ones (Zoom->Jitsi Meet, Whatsapp->XMPP + Telegram, Skype->Nextcloud Talk, Instagram->Pixelfed (experimental for now), GMaps->~OsmAnd + Nextcloud Maps etc) and don't need the rest.
I never see advertising on any of my devices.