Prioritize Mobility Training
Anyone who says mobility work doesn't matter – especially once they're past a certain point in their life – isn't thinking things through. This is especially true if their days, including their job, aren't what anyone would consider active.
Plenty of sitting, poor posture, additional muscle mass, poor muscle recovery, and possibly less conditioning all play a part in why a body can no longer move as well as it used to. A daily routine of mobility work may feel redundant, but it's worth its weight in gold.
Good mobility is actually a product of good strength on each side of a load bearing joint. The thing is, technically sound strength training is dependent on good mobility. One feeds off of the other, and neither can be left out.
In a nutshell, the "strength training builds mobility" argument is only as good as the quality of your reps – and the variety of your exercises. Here are several mobility movements that every lifter should be getting after as part of their warm-up, or in a separate daily session: