Should I consider a fresh reinstallation of my operating system to speed up my PC?

No, a fresh reinstallation of your operating system will not necessarily speed up your PC. You should instead consider running maintenance tasks such as disk cleanup, uninstalling unnecessary programs, disabling startup programs, and checking for malware/spyware. Reinstalling the OS may help if your computer has been infected with malicious software or if you want to upgrade to a newer version of the OS, though.