In all seriousness, of course Inception and Interstellar are very different films to 2001 (just as 2001 is very different to Kubrick's other films, really), and made I think for a very different audience. There actually aren't all that many films that can easily be compared to 2001 - Tarkovsky's Solaris and Stalker are probably as close as you're going to get, and both of those are, relatively, only a little more recent. Malick's The Tree of Life isn't quite a sci-fi film, but always feels to me like a very good companion to 2001.
Perhaps the reason you won't really see much like 2001 ever again is that modern audiences, on the whole, just can't really cope with it - the pacing is regarded as risible and the ambiguity is too much intellectual effort.