Hello and welcome to Microsoft Community!
I am very frustrated that your Chrome browser is working slowly, but I can't pinpoint your specific situation, whether it's an inability to open a web page, or a slow response.
You can try to check if your network environment is abnormal, a poor network may also cause the browser to work slowly.
After confirming that your network is fine, you can reset your Chrome settings or go to the Google Chrome website to re-download and install the latest version of Chrome.
If the browser still works slowly after resetting or reinstalling, you can download Google Chrome for Windows Beta, which is a separate Beta from Chrome, and observe whether it lags or not.
Since you have already reinstalled Windows, I don't think your machine is causing the problem, if the lagging still persists, I suggest you contact Google's related technical support, they will provide a better solution.
I hope you're well.
Best Regards!
Leo - Microsoft Community Support Specialist