If a company sold me a device with a keylogger installed on I would never buy anything from that company again. I would also not let that device on my network, ever.
Normally I'd agree. I refuse to get anything from Lenovo for that reason (and I'm surprised so many linux users are fine with their laptops) but when it comes to cell phones there's no good option, just different degrees of horrible. Your options are basically Apple and Google and anything Google is basically malware designed to collect your personal data. Apple does a little better but is also far more restrictive over what they'll allow you to do and how they'll allow you do it.
In the US we have no privacy rights at all really. Like everything else it's all "agreed to" thanks to a bunch of legalize in their terms of service/user agreement which you can't reject if you want to use a mobile device at all. If I had an option for a cell phone that respected my privacy I'd never buy anything else, but they are all terrible. Apple probably does the best job privacy-wise, and I'm still considering it, but the loss in freedom as far as what I can do on the device would be hard to take. losing Tasker Termux and newpipe alone would kill most of what I want from a mobile device