I read the entire first trilogy and didn't enjoy it. There kind of becomes a plot, but I wouldn't say there's really a grander purpose to it, mostly just a series of events that develop which allow the characters to be displayed. If you like the characters and want to see more of them then keep going. But if you want a strong plot to develop then you might want a different series.

I know people love Abercrombie, but I was completely turned off by this first trilogy so I don't know if you can start with his later stuff.

The most disappointing part of the first trilogy for me was that the story makes references to a series of epic events which happened in the past. If that story would have been written into it's own series I think it would have been much more interesting than what we got.

As for Andy Weir, the Martian was also good. There's enough content that the movie couldn't cover to make it still enjoyable if you've already seen it.