What you are describing is basically a Mortons fork(seemingly different choices that have the same outcome) and as I said you can do that but if you lean on it too much then it becomes a problem.
There is also simply the problem of actually having meaningful choices. You can give tons of options but have them mostly be meaningless(The sub-genre of "Character Building" stories on here are a good example of that) which can give the illusion of having more control than you really have. However readers/players are quick to pick up on the kinds of choices that "matter" and the kind that don't. So another way to do it is only to have choices at points where you are going to make a big change. .
You are right, but I disagree slightly: There are a few ways to create meaningful choices.
One is to introduce a set of character stats (not too many) that actually play a role in the story and can and will be changed often while playing. If you include a set of encounters, each of those giving options on how to react, and each reaction prompting your stats to change, than you can make the reader arrive at a point where he is forced to take turn A by having stat X raised to +5 or to take turn B by having stat Y raised to +5. Or by having found item Z earlier.
I started two stories with variables so far, and while both function differently, the setup in both stories was similar: There is an "exposition" which basically lets you freely decide what to do and building up stats, finding things, defining your character. The important thing is to limit that. You should have broadly a hand full of outcomes on what the character looks in the end, otherwise, yes, you are branching too wide.
But contrary to a simple "character building", when the player arrives at this point, he actually already had a lot of fun (hopefully), has read a lot of text, and could tie his char built to real choices in real situations.
The second part, broadly, would be the main plot, where you make the reader lie in the bed he's made for himself by choosing earlier: Paths are opened or closed based on earlier decisions. Not all of them (because that would spoil the fun too much), but still a lot. The reader, in my opinion, will not feel railroaded, as long as he can clearly understand how a certain development is clearly based on his decisions. Thing is: You don't have to branch off too much here, because you still have those "handful of choices" from the beginning. You stick to those. You simply play through different events and encounters and adventures. Of course, you can open and add small mini-paths based on variables.
The third part would be the finale. That one can branch off widely again, because each ending can be a real ending and you don't have to bother anymore. That way, you have both: Real choices, but a range of paths that is manageable.
Even better: If you work together on such a story, each author can take care on a specific path of choices, adding little touches here and there, while still cooperating on the main plot.
However even then you can run into the problem of doubling up on things. Say you have a scene where a character is going to live or die. In one they live and the other they die but you may find that most of the events that follow don't change a whole bunch but now you need to have two threads going to support both of the choices. Since most people are doing this for fun they are unlikly to want to go to the hassle of having to double up on writing for this.
Best way is to find branches which do have an impact, but won't pop up and influence every second (like life and death). So you can still go one main path, but slightly branching off from time to time to come back afterwards. That way, the reader will still experience different things, but the work is manageable.
