There's no way a Tablet can give a good Factorio experience.
Fundamentally, the user-interface is baked into the game. Every button-click, every key, has a purpose. Lets list the things that you must do in Factorio:
1. Move the avatar -- WASD keys + shoot + weapon select. The combat system includes grenades of various types, auto-firing machineguns, and deployment of various "combat bots".
Given the typical tablet gestures (click, click-and-hold, two-finger press, etc. etc.), there's simply not enough gestures to handle all movement and battle commands.
2. Building -- Even in combat, building items is common. I often build power-poles + electric turrets as part of my combat push into biter-land. Buildings can be rotated (4-rotations), shadow-built (you don't place a real building: just a shadow of one. Then a bot places a real one at a later time), or copy/pasted.
Given the typical tablet gestures (click, click-and-hold, two-finger press, etc. etc.), there's simply not enough gestures to handle all building commands.
3. Advanced UIs -- #1 and #2 give you an idea of how detailed the controls of Factorio are. But this extends dramatically to all entities in the game. Editing an inserter? That's a custom GUI (inserter filters, inserter stack sizes, inserter direction, inserter-rotation). Building a train-track? Custom GUI. Combinator logic? Custom GUI. Train-scheduling? Custom GUI.
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Maybe a Factorio could be rebuilt from scratch on the Tablet form factor. But I severely doubt it. Almost every key on the keyboard is bound to a command, all mouse buttons (zoom, scroll, right-click, left click, and more) are bound to commands.
And there are even "vi-like" hotkeys for the shortcut bar, allowing you to swap custom items into your toolbelt because we still don't have enough buttons to do things in Factorio.
A hypothetical "Tablet Factorio" would have to grossly simplify mechanics, and reduce the number of "modes" the game has. Its hard to tell that all these modes exist in Factorio, because the UI just so naturally teaches you the hotkeys and the buttons to push in all circumstances. But when you break it down, there's "too many modes" to really cram into a GUI.
And mind you: unlike Civilization, Factorio is Realtime. Biters are FAR faster than the player in the early game, they bum-rush you and block your movement. Every fraction of a second you waste with controls is another biter that comes up to start nom-noming you. Touch-screen interfaces are just too slow for combat.
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EDIT: And all of these GUIs interact with each other in "logical" ways. If you want to drive a tank (or even a train) while ordering bots to deploy blueprinted Laser Turrets, you can do that in Factorio.
But maybe the biter swarm was stronger than you expected, so you're going to retreat. You disable your personal roboport, swap out for some exoskeletons (+Speed), exit the tank, load a nuclear bomb into the rocket launcher, then run back to your base while nuking the biters who are chasing you.
You can seamlessly transition between situations, realtime. All the GUIs of Factorio interact with each other seamlessly.