Your point is incorrect. The energy in the fuel used to fly a plane can also be used to power a gas turbine electrical generator and thereby a computer. They are, at least in principle, fungible.

Their energy consumptions are fungible, but that doesn't mean the content or value of any particular training run or international flight is comparable.

Some flights run totally empty (airlines need to keep their precious routes) which uses a marginally smaller amount of fuel than a full plane, but provides no real value (nobody was transported to a location they wanted to be in). Other flights are normal, but also carry an individual of great importance, or play a strategic role.

Some training runs waste a bunch of power and then get thrown away. Others go on to serve users and make billions of dollars.

The energy cost is only a proxy for the fully loaded "value" of what you create with your energy consumption. That's why it's not comparable.