The question is more posed at the outcome. I'm not suggesting that you force the players on one exact route and that their choices don't change how they get there. Moreso that all of these spells don't actually give casters this huge advantage that it appears to be. Whether you fight the ogres, charm then or skip them entirely you're still able to get past that encounter. This is true of linear or sandbox worlds. If there's a flying city, someone at one point made it there so in my world building having the flight spell isn't going to be a prerequisite to each it(in fact it probably wouldn't work anyways). It's specifically because I'm not tailoring the world to match the parties capabilities that having the spells or not having them can both achieve the same result.