Why relationships are so fleeting these days?

Is it just me or does anyone else feel the same? I feel like as I get older, relationships are getting so shallow, thin and fleeting? Why is it so hard to someone commit to another? I've been working hard on myself to not let intrusive thoughts lead me into thinking: it's my fault! When I clearly do whatever I can to keep the ones I love close to me. But people seem to not appreaciate it anymore.