But browsers already have that functionality built in, why go through DDG for that? (well, Chrome and Firefox do, not sure about others)
If others = Opera, then yes, they came up with that first :)
I've been using those kinds of keyword search shortcuts for years before switching to DDG by default.
The realisation was that having 100s (maybe 1000s already) of easily-guessable search shortcuts pre-programmed with DDG's !bang syntax is way more useful than having top configure 10-20 of them by yourself (and forgetting most of them when you reinstall a browser). Definitely worth the extra "!" keystroke and redirect :) [especially given DDG doesn't track you via that redirect].
Just the amount of times where you know the most useful (and probably top) result on Google will be Wikipedia makes DDG worth it. Saves a click. But for me it saves a click very often.
If I need Google occasionally I just append !g, but it's just one of the many other places I use !bangs for finding stuff.