Likely varies by jurisdiction -- as it stands there is a fairly big split between countries that deem you having accepted the terms and conditions when you drop the cash vs those that would allow you to return a device if you deem the terms unacceptable to you and that could play into things.
Also "own" when it comes to software is a tricky concept. Obviously you are not going to get any kind of IP rights to the device but what you get to resell varies. I don't know enough here about what goes, and you will likely have rulings along the lines of essential components of the device (which would include the firmware) can be tied to it. More recently we are finally seeing movement on courts preventing software companies restricting resale of software goods too (technically it has existed for many years, and practically/theoretically longer still even if it was not enforced).
All that said outside of modded consoles I have never seen anybody blocked from reselling a consumer* version of a game console so that is what most people are concerned with. The other main concern is whether "my device, my rules" applies here and you can indeed mod things, and this definitely varies by jurisdiction but again all they ever really do** is ban people from online services.
*former dev kits, reviewer kits and the like are a different matter.
**if you ever see a newspaper headline about mod shop raided then every time I have ever looked into it then they have been also selling pirated games with the things. The reason you tend to hear about the mod shop part is most newspapers don't dig and just regurgitate the press release from the company in question. Closest I have to any kind of exception here is the more recent anti KODI efforts by some places, though even they were more after people installing plugins of dubious legality.
