"These days, I use Microsoft's built in anti-malware, along with Malwarebytes (if needed)."
Just to make sure of my knowledge of Micro$haft "protection" built into W10 and available as downloads for earlier systems I checked here:
https://www.microsoft.com/en-us/wdsi/products and it verified what I know. Simply put, every one is anti-virus, not anti-malware. That's what Malwarebytes is for, not IF needed, ALWAYS needed providing real time protection in addition to scheduled scans, Micro$haft provides no protection against malware and never has. Protection against rootkits is essential, and with ransomware on the rise companies are working on it but have not yet perfected it because of its many variants. Meanwhile a good backup system is advised and in addition to weekly AV scans, daily if you're paranoid, a weekly scan with Malwarebytes is strongly advised.
"These days the anti-malware industry is a little too "black box" for me."
And you're an IT guy?
"I don't need some kind of herculean anti-malware behemoth slowing my machines down and beating up the drives."
Come up to date then, those days are long gone. I hate repeating myself, so if you're interested back up a bit and read what I use "post AVG/Avast/Hitman Pro Apocalypse" scanning weekly quietly in the background with no noticeable change in machine performance and drives gently purring away.