Most infections stem from email attachments and public torrent trackers.
So as long as you don't open attachments from unknown senders and are cautious when using public torrents (no judgement from me) Windows Defender if perfectly good.
I used to always install AVG free, never in my life have I paid for antivirus, never will.
Now I only use defender, as they all seem pretty much the same, some will catch what others miss and vice-versa
Since win10 even I've had trouble accessing files (contact administrator!!!) and I'm the sole user and have admin rights LOL (looking at you "Owner - TrustedInstaller) so what chance does a virus or malware have LOL
Though a scan from malwarebytes isn't a bad thing now and then