I feel this too. I could only guess at the cause. Maybe it's just the demographics of social media swinging younger, or those struggling simply being more vocal online. Both? Neither?
I'm an older millennial, but do own a home and have kids. I have friends and acquaintances, - some who didn't go to college - that also own homes and have kids. Sure, the houses might be modest (and include PMI payments for some), and nobody's taking lavish vacations every year, but it's certainly not as bleak as my social feeds always make it out to be.
I'm with you here. My up vote won't help much, but you're spot on. This thread is so strange.