You can usually downgrade a package or two, but there’s no good way to go backwards that far. You’d have to reinstall.
But, I think you are going on the logic that each new version is more bloated and requires faster and better machines. That’s not actually the case. In fact, we’ve done some things in newer versions which should have a significant performance benefit on a system like that. And things like graphics drivers are just going to get better, not worse.
Can you tell us more about the specific performance problems you are seeing? Are you using Fedora Workstation? You might find something like Xfce to be a bit more lightweight.
Also, something to think about: the obvious bottleneck on that system is RAM. A quick search suggests that at least some versions of the Acer ES 15 can be upgraded to up to 16GB, which would make a enormous difference and looks like it’d cost less than $100. No matter what the operating system, web browsers these days are very hungry, so even going to 8 or 12 would be a noticeable improvement.