I learned about this game a few years ago. My first impression was very strong. I thought this game had the potential to be way ahead of everything I had seen. But over time, I began to notice that the game had serious problems, primarily related to the linearity and monotony of the gameplay, as well as the dominance of economics over war (actually, this is one of the main reasons for the linearity, but more on that later), when everything comes down to upgrading extractors and creating super units. But at the same time, I still had a feeling that the potential of this game is much, much higher. For about two years, I tried to find and solve the problems limiting the capabilities of this game through modding. And today I have a more or less complete understanding of the problems of global balance, the main one of which I want to explain here. So...
Build Time.
In my opinion, this is the main problem of the game. This problem literally DESTROYS the gameplay. What's the matter? The Build Time for different branches of the military is different, but the most important thing is that the Build Time of buildings, including economic ones, is several times less than the Build Time of units. This creates a huge imbalance between the economy and the war. The prices of units and buildings themselves are quite balanced, but the fact that with a comparable price for a T2 extractor and T3 mobile artillery, the latter takes more than 4 times longer to build with the same Build Power, leads to the fact that investing in the economy is much more profitable, simply because it is faster. This is what leads to linearity and monotony, because war cannot compete with the economy, and the economy is always the same. As a possible solution, in the "Advanced Bases" mod (available in the FAF repository), the Build Time increased: fleet - by 1.5 times, air - by 2.5 - 6 times, buildings - by 5 times, and the Build Time of some individual categories of units additionally adjusted. Moreover, the adjustment was made taking into account mass cost and energy cost.
Remember that the most important resource in game is TIME. I suspect that if this problem is solved, Supreme Commander can become better than Starcraft 2. I am not exaggerating at all.