So do you think that running backs are still crucial to a team's success or are they just secondary in today's NFL to quarterbacks and wide receivers?
I do not at all think the Running Back position is becoming obsolete. It may be the "uncool" way to build a good team, but it is still possible to be a great team by running the ball effectively. The best example of this is the 2009 New York Jets. They couldn't pass the ball well (thanks to a Rookie QB), but managed to make it to the AFC Championship Game thanks to the #1 rushing game in the NFL (and the #1 defense). Everyone said that their offensive attack was a "throwback" offense, because it isn't the common way to have a productive offense anymore. But just because it isn't done anymore doesn't mean it is obsolete, or that it can't work. The 2008 Ravens were the same way (again, thanks to a rookie QB). They ran the ball well (and played good D), and were able to make it to the AFC Championship game, despite a so-so passing game.
I understand why you would think that the running back has become obsolete. To me, there are 3 reasons why this opinion has been built in recent years.
1.
The decline of the straight up running game in college. With more and more teams becoming pass oriented or option oriented, running backs never get to reach their collegiate potential, which leads to both running backs not gaining enough publicity to be a #1 overall pick, and running backs falling deeper in the draft (where they usually prove to be good picks).
2.
The advent of the 2-back system in the NFL. Because of the amount of contact running backs take, their lifespan in the NFL used to be minimal, especially for physical runners. Now, I can't think of a single team that utilizes a 1 back system. Now teams, instead of looking for 1 amazing running back, would rather have 2 very good running backs.
3.
The increased emphasis on the passing game in the NFL. Most teams now are leaning heavily on the passing game. This is not necessarily due to the running back, but rather the quarterback. The highest paid player on most every team is the quarterback. Running the ball takes the ball out of these elite players hands.
Bonus Question: Will it be easier or harder for a running back to get into the Hall of Fame if he starts his career now or ten years earlier?
It may be a little harder, but I think at the end of the day the truly Hall-Of-Fame worthy players will stand out, and get into the Hall. Guys like LaDainian Tomlinson will have no problem getting in 5 years after their last game. Maybe marginal Hall-of-Famers, or guys who don't belong won't get as much consideration, but Hall-Of-Fame caliber players will always find a way to shine, and get enshrined.