If I installed AV software it would immediately slow the computer to a crawl, sometimes give false positives and always cause problems with other software. No thanks.
Slow to a crawl? Sometimes give false positives? Always cause problems with other software?
Where on earth did you get all that from? Something you read? Because it's certainly not from experience. Antivirus products have a low single-digit extra CPU load. Usually the only way to notice it is to run a benchmark program.
The last time I had a false positive was back in the DOS days, when viruses and antivirus programs, were in their infancy.
And especially "always causes problems with other software"? I call bullshit! I've never experienced it and never read about it in all the years of reading antivirus reviews. NEVER. If it does happen it must be extraordinarily rare, and emphatically NOT "always".
Honestly, I don't know why people can't just speak truthfully and unemotionally about this stuff instead of all this exaggeration.
Microsoft leaned into security because it is a major target, and most people don't give it credit for the work and success it has had.
One of the primary reasons you no longer have the issues or loads associated with AV and Anti-malware is these security products can take advantage of the M$ work.
Secure boot and kernel signature verification are great stuff. M$ also digitally signs their entire set of OS files, drivers, etc etc. They will warn you if you try to run code that isn't signed.
AV and AM products use these features. They validate signatures and checksums, which avoids scanning large portions of the file system. Only the User's created or downloaded files, etc., must be scanned. There are then "reputation" checksums. This is a feature of modern security tools that many people are unaware of. Every file the security software scans is assigned a signature. That data is shared across the security software industry to determine the reputation of files in general. This greatly speeds up future checks on non-signed content. If you want to know worrisome stuff about this feature, that's a topic in itself.
Many of these practices have made it to Linux, but the big problem on the Linux side is the widespread practice of disabling Secure Boot. The AV products on Linux trust GPG signatures, but if the system isn't secure from boot (secure boot disabled), it's a defeated system.