The problem with those cheap phones is that your private information
will be mercilessly sucked into the Google cloud. Some of that is
disguised as perfectly innocent and helpful features: contacts
syncing, back-ups, connecting more easily to WiFis, etc.
of course it's extra work, but it's not rocket science. so if you really
care about privacy, it's trivial to do. but as pointed out: most people
don't, no matter if they have a cheap phone or not.
the parent claimed that you pay for these cheap phones with your private data, which is not true. if you care about that (which > 99.8% of the population don't do) you are able to use those phones with those features without handing over your data to google.