Cost is really the big differentiating factor in favor of corded. Convenience is not. I had a $60 corded hedge trimmer that anytime I wanted to use it I'd have to drag out 100+ feet of power cord. No matter how careful I was, I'd inevitably cut into the cord. That got old. Same with the 2 cycle and 4 cycle weed eaters. Dragging out the fuel, storing it, and starting it was often a hassle.
I switched to M18 stuff and would never see myself going back. For my yard, a little over 2 acres, I can weed eat everything, usually taking about 45 minutes, on one battery, and power has never been an issue.
To be fair, I have a couple expensive "Forge" battery for outside stuff, which will run a long time for most tasks. At this point the only outside tool I have left that's not battery powered is my 20" Echo chainsaw. Since I also have an M18 chainsaw, the Echo rarely ever sees any use.
Bottom line, cost is a huge negative on the cordless stuff. However, I'm at a point where convenience and time savings are my most important concerns. That said, each person has to follow their own path with tools, based on factors that are most important to them!