I think some people are a little too keen with the 'forget keywords and focus on topics' line, or perhaps it's misunderstood.
Google HAS moved away from keywords: the patents I've read about, the SERPs I've seen, and my own (pretty limited) direct observations for some time make that much clear.
But keywords, where you can verify the precise word or phrase, its search volume and user intent from AdWords, are still very useful for one reason: THAT IS WHAT THE USER TYPED IN. That is what they expect to see. It's called reinforcement, and in PPC it works very well.
Now, Google will attempt to 'understand' their query - and it might be a lazy query - but, all other things being equal, using the same terms that the user does prominently in your copy is going to help on any and all levels.
Keywords in metatags are kind of deprecated
As far as I am aware they have been totally irrelevant for years.
... while in... descriptions
Again, last I checked, the meta description has no direct ranking effect, in that Google does not retrieve a page with a unique gibberish phrase in its meta description even when you search for that phrase. But, as with PPC, the right keywords in the description will increase the chance that it is shown for the user's query so again you have reinforcement.