No one cares about the efficiency of the tiny battery in your phone. But if charging and discharging a Tesla used twice as much energy as burning gasoline directly then people would probably care.
At some level of inefficiency, an energy solution can indeed become useless at scale.
That depends though on a bunch of factors including base price of electricity, renewable potential and how easily hydrogen can be shipped.
There are a few developed countries I can think of that have vast renewable capacity but the distances between the optimum location for renewables make it impractical at present.
Also modern nuclear plants are an option if you want to produce vast amounts of electricity with a smaller carbon footprint than coal/gas.
At some level of inefficiency, an energy solution can indeed become useless at scale.