"Since I know at time 1, if the price has fallen to 90 or rose to 110, I will get to decide if I want to get into the contract or not." Assuming you can enter at any price you want is flawed (unless you think of an option).
You ARE in the futures contract (or not). If you enter into a future, that is it (ignoring that you can get out of it whenever the market is open). If the price moves against you, you would have been better off if you had not entered into it in the first place. A future neutralizes risk by fixing the price but it is an obligation. A key aspect of hedging with futures is that you will never know if it will be better than the outcome without hedging. If you could simply say at some time t in the future that you want to enter at 105, than you actually own an option. If not, the future price will be determined by the market and you have zero choice what that will be. That is also the reason you have zero cost (well kind of, as you also have to post margin). The price will be such that it is "fair" and no one is better off, hence no one needs to be compensated.
An option on the other hand is (like) insurance. It protects against adverse events (price movements) while allowing one to benefit from favorable price movements (where your future will make you wish you wouldn't have entered it).
However, I think there is an interesting side aspect of this question. Why do you actually enter an option on the future and not the underlying? Do you know the price of WTI? Probably yes. Do you know Alaska North Slope, Canada Select, Light Louisiana Sweet or Gulf Deepwater Sour? Probably not.
If you google WTI price, have a look at the results. These are all futures prices, as they play the primary role of price discovery (nowadays). That is also the price you will have to take at time t (and not your assumed 105). In many cases (especially for commodities, but also for treasury bonds etc.), futures are much more liquid and easier to trade than the underlying itself. Also, exercising the option on a future does not lead to delivery of the underlying. OK, you could have cash settled options on spot prices, but the standardization and liquidity is the real point here.
The exchanges usually do not have spot trading for commodities (and in some cases, how do you actually trade the S&P500 Index? E-Mini's are very liquid on the other hand). Since (at least traditionally) there was a lot of PIT trading, and futures and options traded side by side, trading, arbitraging and hedging was a lot easier in futures and options.
Long story short, if you want to know today what price you can enter into your future at some time t, you need an option.