It's not as simple as that. A trip from the airport to the strip in a taxi will be cheaper via taxi than Uber - they have a fixed rate but Uber uses surge pricing so when your flight lands and everyone hits Uber at once the price goes up significantly -- but if you are at an off time then Uber is cheaper, check the Uber app and grab one if its off-surge. Airport to downtown is hit or miss, and you'll use the meter or the surge pricing depending on if you hit a surge for when you land. If you can get an off time then Uber is much less expensive.

Going back to the airport Uber is always the way to go.

https://thepointsguy.com/news/las-vegas-sets-flat-rate-taxi-fares-between-the-airport-and-the-strip/