You could queue multiple units to build, adding in multiples of 1 or 5 (Supreme Commander later made this into an even more powerful system). You could queue an infinite amount of orders for each of your units - not just pathing waypoints but everything. I used to set my Commander up to do about 15 minutes of building at the start of the game.
You could tell buildings to "move" somewhere and all units coming out of those buildings would go there when built. You could tell construction units to patrol and they'd automatically repair damaged units and collect resources on the way. You could tell construction units to assist buildings and they'd help build new units. You could press Ctrl-A to select all units, Ctrl-W to select all fighting units, and other ones for airplanes, ships etc. And so on.
I think it pretty much shaped the attitude I have today where in game design, I think everything that has one "correct" answer should be automated away, and everything else made as simple as possible.
Of course when TA first came out the battle wasn't yet between TA and Starcraft, but between TA and Dark Reign.
Also, TA supports all screen resolutions your monitor does, so far from needing a Remaster, TA still looks surprisingly good today at high resolution. The interface (which is designed to work with 640x480) quickly gets tiny though.
This made the green race (forget their name) in Supreme Commander quite overpowered - as artillery doesn't suffer from line-of-fire and that race had the most powerful artillery.
The simulation of projectiles also made the game run like a dog, but we loved that slow dog.