I don't think you can really compare both of these games... both are about building factories, but that's it. Factorio is another world of complexity comparing to Satisfactory
I'm not sure how one could measure the complexity in terms of game mechanics, but there is definitely a large amount of overlap in that complexity I would say. Both games have machines to mine, assemblers of increasing complexity, belts to connect them, a variety of possible inputs and outputs. There are things in Satisfactory that's not in Factorio and vice versa -- Satisfactory has a space elevator, Factorio has rockets. I'm no expert on these games but from the outside it doesn't look like one is twice as complex as the other in terms of mechanics.
Having played both, Satisfactory doesn't come close to the scale Factorio has. Especially when it comes to late game scaling, I have 20k assemblers on my longest running save.