I disagree, because it Is a high level of abstraction (making it absurdly unnecessarily specific is unnecessary)
The 'Food' resource is probably the most specific.. but the currency resource is not less abstract than 'research' or 'culture'.
Why not use "energy" as the resource to obtain technologies or get virtues (you need energy to run labs, and to run the servers with cat pictures/philosophical treatises)
Instead you just use the term research (and a picture of a flask) or culture (and can't tell what it is a picture of) ... why not the term "wealth"/"currency"/"trade"/"finance"/"economy" etc. (and a picture that doesn't look like any energy symbol I'm familiar with)
The symbol may just be a placeholder, we don't know.
You could use a lot of other labels, they're just labels. It's such a high level abstraction of nebulous processes you could make a case for many different labels. Any of which will not match up perfectly to what you can do in the game with it.
Energy is fine. You could rush a project with more work (energy expenditure), or look at it as rushing a project with more pay for more work (currency), or rush a project by procuring more materials faster (production).
In the end no label will encompass all those things and fit the way that X is procured. Wealth is pretty good, but too encompassing. Cogs would be wealth. Food would be wealth. Your land is wealth. So you could make the argument that if you use Wealth, you only need Wealth and it doesn't make sense to have anything else. That would be a very bad thing for the game. Of course you could still use the label and it would be ok. Currency, Energy, Trade, Finance on the other hand are too narrow. They make sense in some known applications/effects/procurement, but don't cover everything you can do with it.
But the game needs a label for this abstraction of rather divergent things (compensate other factions, reclaim power sources, speed up projects, use/harvest energy of natural resources, effect of trade routes, and perhaps other things). Energy works as well as many other possibilities. If they split it up into more well-defined components (Energy, Trade) then you could get labels that fit better. But it may not be better for gameplay, which is the ultimate consideration.