Not so much design failure, as something that’s been updated in newer models for the more extreme situations like this seems to be. Modern ones do, this is an older plane before the battery systems were part of it. And it never upgraded to add that.

The bird strike didn’t cause power loss. For total power loss that would mean both engines were off for some reason. Which is extremely rare. Most bird strikes don’t actually take out an engine, most birds just aren’t big enough to cause that damage. Even when they do it’s rare for multiple engines to get struck and damaged enough to do that.

One possibility is that after the strike the pilots either cut fuel to the wrong engine, or to both engines which in turn meant no power generation, and would match the currently known timeline. There is a limited backup power system for things like instrumentation, but that system doesn’t power the data recorders.

Loss of both engines would also explain the fast turnaround and landing on the runway opposite direction instead of a regular go around, since they wouldn’t have power to climb back out, and limited to no hydraulics for things like flaps and regular landing gear deployment.

Although emergency gear deployment should just rely on gravity… And that doesn’t seem to have happened, so there’s questions about that as well.

Not to mention the context or another landing gear issue on a different plane from the same airline just days after this accident.