People are going to buy new phones regardless. You not buying used phones is not going to change that.

Buying used or refurbished keeps the devices they‘d throw away (or keep in a drawer for 10 years, then throw away), if they couldn’t sell them, from landfills.

Also, I know plenty of people who are well off that buy second hand phones and even more people who couldn’t even afford a Fairphone (which starts at almost 500€ for a 4 and 650€ for a 5) that buy a brand new 200-300€ phone every two years.

And those low end phones are the least environmentally friendly because they‘re definitely unethically made they most likely break more quickly than higher end options, they usually don’t get updates for very long, if at all, and there’s no noteworthy second hand market for them because people just throw them away (or into a drawer) if the phone stops working or when they feel like getting a new one, because who buys a 2 year old low end phone second hand?

Buying used instead is a great option. You get a higher end device for cheaper without anything new having to be made for you. It‘ll still last you years and you’ll have a better experience than with a cheap new phone.

Yes, it would be better if all phones were ethically produced, easy to repair and would last a long time. Especially if there are ethically phones in the sub 300€ market. Won’t be easy to achieve, if at all, and wouldn’t stop blind consumerism but it would make for an even better second hand market. Because, you know what’s better than a fairphone? A second hand fairphone.