Corporate environment is very different though, you wouldn't be running the consumer version of Defender in there because you need greater defence in depth, a higher efficacy rate and something that can be deployed and managed remotely at scale. Go back a few years and I agree, Defender was a joke but it's got a lot better. It's far from perfect but it does decent enough job these days. The average person for home use doesn't need anything too complex, the three main problems are phishing, downloading infected files and drive-by downloads from ads. The consumer version of Defender, an ad-blocker and the built-in capabilities in Edge/Chrome/Outlook protect you from a significant portion of those things. The main focus of threat actors against home users is for data and account access because they're less likely to get a decent payoff from ransomware compared to targeting a business. It doesn't hurt to add more layers to your defences of course but for a lot of people it's overkill.