The main concept is to protect you from yourself. If you accidentally fall into a phishing scam or download malware. It won't be able to install an application without the admin credentials since now you are using a regular user for your day to day activities with less permission.
and install all the extensions that you need for that Profile. Keep your main Profile where you check your email / social media free of those extensions. This is also useful if / when you want to separate your personal email / browsing from work / project related.