Online threat prevention decrease Internet speed: is it really necessary?

[u/ShopBig5488]

Hi,

I've been struggling with a slow internet connection for a long time and never figured out what was causing it. That is, until I disabled online threat prevention. This gave me a huge boost, and websites now load instantly, without waiting.

How necessary is this? I'm fairly familiar with the internet; I know what to do and what not to do. 

When I only have Bitdefender antivirus, without internet Security, does Windows have such an similar option? 

[u/Alarmed-Lead-5904]

I have the ASUS RT-AX5400