Is windows phone now considered a basic phone?
I don't think so. It's a smartphone platform (or rather, it was) ran by dumb people. So it failed.
In all seriousness, again, no, they aren't. However, they are not as advanced as the latest Android or iOS devices and may not have the latest version of popular apps (or any version at all).
But if you just want a cheap smartphone to take when you go out drinking (whilst you leave the expensive phone at home) or you just need a smartphone that does internet, email and the basics of social media then they are still fine and you can probably get the 950XL or X3 or Alcatel device at bargain prices.
I haven't given up on Windows Phone. The Elite X3 is my main phone and it does all that I need from a phone (but your needs may vary in terms of what you expect or want from a phone) so I have no complaints no reason to switch to another platform right now.