that's true to an extent, but i think every team other than the saints has to deal with cap realities. washington is feeling it now and they dont even have a qb. philly is starting to see it too and will for sure once hurts' extension really kicks in. the chiefs traded away the best receiver in football because of it. the bills just lost some good players because allen's contract kicked in. vikings too because kirk is making $45 mil.
as for the lions, all these good young players are eventually going to get paid. as you point out, the way to beat that is to keep the pipeline of good young players coming.
the easiest way to keep those guys is to not have to pay one player $50 million. but as mb will point out, good qbs cost money and they are the most important position in sports. if you have one you should keep them. is goff that player? reasonable minds can differ on that. lol.