Bad performance, need ideas

I have a 2014 Chevy cruse LT. It has about 107500 miles on it… The check engine light is not on but the performance has gotten bad. It does not like getting up and go anymore. The fuel economy is has gotten bad. I’ve taken it to a Chevy dealership and to another mechanic shop and they could figure out what is wrong with it. Any ideas would help.

How would a bunch of folks on the internet who’ve not done any diagnostics to your car give a better answer than a dealer mechanic and an indi mechanic? And you didn’t even tell us what engine you have.

Given that, the only thing I can tell you is trade it in on a new car.

Has routine maintenance been done? Oil changes spark plugs gas and air filters, trans fluid filter etc??

Lack of power could point to a clogged air filter, clogged converter, clogged fuel filter, or a worn out engine although in theory at least that should not be the case at 107k miles.

Without car in hand and sparse info the first thing I would do is connect a vacuum gauge. That is quick, easy, and can reveal a lot of info in a few seconds. If one has or knows how to read the gauge that is.
Another possibility (a.k.a. a guess…) could be an intake tract leak between the throttle body and MAF sensor.