Whether or not you can come off insulin heavily depends on what type of diabetes you have and how much damage your pancreas has sustained, as well as how you manage your diet.
People with the autoimmune variety of diabetes, or conditions that damaged the islets beyond repair, are insulin dependent for life. The body can't produce (enough) insulin anymore so it needs to be supplied through injections or a pump. Short from experimental organ transplants this is not going to get better.
People with type 2 might fall into the former category due to damage to the pancreas, or just because their diet and exercise regime alongside oral meds don't work for them. Some T2s can come off insulin if they strictly manage their diet and exercise (often this means low carbing, but it's not for everyone). This is not a guarantee however.
The cons of injections? You die without them if you need them. You'll end up with raging high values and DKA. Unchecked diabetes increases the risk for long-term complications dramatically.
The pros: you'll be able to get good values, you'll feel better, and be healthier overall. Insulin is just a medication to help you manage your condition. It's not a verdict on your choices and nothing to be ashamed of. If you need it, you need it. MDI (multiple daily injections) allow you to be super flexible with your food and daily routines, while a mix insulin (approx. 2 injections a day) requires you to adhere to a strict diet and carb counting. A pump can also work for people for whom MDI aren't cutting it.
