Well, don't worry. The base game is easy to complete in ~20 hours. Nintendo won't allow mods, so you won't have access to the add-ons that boost a single game (Krastorio, SpaceX, Bob's) into the 1000+ hour range.
Also, I disagree that it's easy to complete in 20 hours. The speedrun currently sits at 1h25m and while <20hr is quite possible for anyone to accomplish, it's pretty unrealistic for a first run where you'll likely hit a few progress snags.
Though, unlike some other games, the progress never slows down - misallocating early skill points in some games causes serious pain making up the same points without the proper tools at an exponentially increasing cost... in Factorio a tech is always the same cost so researching out of order simply delays how quickly you can become more efficient.
Given the availability of blueprint imports and YouTube, I don't think 20 hours is unrealistic. There's just too much content out there now on exactly what to do and when -- jump start base, main bus, bots, modules, launch, trains. When I originally got the game, Nilaus hadn't started doing megabase tutorial videos.
It sucks, but over time the Internet spoils games completely. Mods improve the situation because the content can be too niche for mainstream creators to profitably monetize. Kr+SpaceX is basically impossible to cover outside of Discord.
So... 100+ hours to research all this, and then <20 hours to complete the game :)
F... advanced oil processing