LaDainian Tomlinson turned into a much less successful back at age 30 without hardly any signs of wearing down during age 29.
Adrian Peterson turned into a much less successful back at age 31 without hardly any signs of wearing down during the age 30 season.
The list goes on and on and on for bell cows like Kamara, but you get the point and the consistency of the decline happening at age 30 and 31 is great. The likelihood of Kamara becoming less than an average back this coming season or staying injured, is good and its even greater the following season.
Miller has only proven he can't stay on the field. As of right now, Clyde is our most dependable back that will be less than 30 years old this coming season and with his history of missing practices/games because of PTSD, even he can't be counted on game in and game out for a full season.
(this is mostly directed at who you're quoting)
We saw this past season how unsuccessful our passing game was even when everyone was healthy. We still mostly moved the ball on the ground with Kamara and Taysom. Teams without gun slinging QB's often get 8 in the box. We can't afford to lack on the RB position until we have a franchise QB.
We are a running team. We are NOT a passing team. Just like Loomis/Payton needed to draft Brees replacement prior to his retirement, we are now in the same boat but at RB. We need to start looking for Kamara's replacement because as of right now if Kamara declines this season with our current roster we will not only be a non-passing team, we'll also be a non-running team.
RB is a need. Not a luxury.