How much do you challenge your hip motion/mobility into EXTENSION? We live our lives in flexed positions (sit, bend, drive, etc.) and we rarely motion, stretch, posture into extended positions. Even if we do deign to stretch our hip flexors and quads, we tend to arch our low backs (essentially anterior pelvic tilt) and perpetuate the "shortened state" of our front flexor muscles as well as the front aspect of the hip capsule.
Your body is indeed very "use it or lose it" and what happens over time is that our hip joint capsules 'tighten' and we begin to lose isolated hip motion. This may initially appear as "feeling stiff", sharp pinching pains across the low back, chronic tight quads, chronic tight pigeon pose, etc. This growing stiffness and loss of flexibility is not simply because our muscles are 'getting tight', it is a response to losing hip joint mobility.
Promoting some of these positions, stretches, and work-out motions to gain or maintain hip extension is extremely important to avoid hip labrum surgery/total hip replacement or even chronic low back pain!
Best physical therapy practice includes lifestyle and habit changes so you don't drift back into your old positions, movements, postures, etc. that your pain originated from! It also includes manual skills that help you get there efficiently and helps make your day more towards function rather than having to warm-up or stretch or massage something for 10min before you get going!