The business is not without risks. The income you desire is possible. There are people out there making it right now. However, there are also a lot of good folks driving the same kind of trucks for the same kind of carriers that don't make the kind of money you speak of.
It's easy to be a top-income earner in the industry IF you are willing to do what the top-earners do. Before you enter the industry with the expectation of $90,000 net after expenses (and before taxes?) as a driving team, it would be wise to compare your business plan to those of the people that are actually earning that kind of money. $90,000 net after expenses is doable. It is also a very ambitious goal.
It's not just about the percentage of loads you accept. Numerous other factors come into play. How long will you remain in service? 95%? 70%? Will you be in a reliable truck? How much time off will you take for family and vacations? Will you have a reefer? What creature comforts are you willing to live without in the truck? How much debt will you carry? How much money are you willing to spend (save) on food? etc. etc. etc.
I commend you for having an income goal set before you start. That in itself gives you a leg up on those that have tried and failed. If you have not already done so, use the goal-setting wisdom that you have already demonstrated to formulate a written business plan that will maximize your liklihood of success.
I hope you go for it. It's always a joy to meet success-oriented drivers on the road.