It’s got the LFX engine. If you look online, there are several examples of Impalas and Lacrosses with the LFX engine and tons of miles. 2012+ had the timing chain issues resolved. The 2016 was the last year on the Lacrosse I believe and all the issues were ironed out by then. The 6T70 is also a fairly reliable transmission. A neighbor has a 2013 Impala with that powertrain combo and I think he’s just north of 220k miles. It’s been reliable to him outside of the usual wheel bearings and climate control actuator issues.
@clinebarger can probably chime in with his expansive experience on GM powertrains.
These are great cars, there just weren't many sold which is why you're not getting a lot of feedback. The luxury full size car market had died by 2016.
My 2014 lacrosse was reliable but it succumbed to the noisy blend doors phenomena at ~34k miles. The doors would make a creaking/groaning noise when I selected among the HVAC modes. I replaced the actuators myself (quite an undertaking) to no avail. I found the noise so annoying that I attempted to remove the dashboard to expose the blend doors but lacked the proper tools and I was forced to abandon project before completion. The system worked properly but sounded like a bag of bolts, which was unacceptable in a car of the Lacrosse's caliber. I recently rented a '23 Malibu with exactly the same problem emerging at only 21k miles. I recommend the Lacrosse and enjoyed its performance and comfort, but decide whether you can live with its (likely) noisy blend doors.