Technically, they're because of the filesystem in use: it's providing the APIs these garbage-ware utilize... which causes the performance issues ( ◠ ‿ ・ ) —
File system filter drives apply to all (RW) file systems on Windows. It's not exclusive to NTFS or ReFS.
Windows has an extensible model. It's a different approach from most (all?) other OSes. It offers a different set of features.
Sure, AV could perhaps be done in a different manner that would be more effective/faster, I can't comment on that as I lack the insight required -- only MSFTies that work on kernel code could respond in any authoritative way.
I was of the understanding that these sync APIs are only available on Windows filesystems, so a fat32 formatted filesystem wouldn't suffer the same performance impact, which is why windows provides "virtual drives" for performance on their cloud instances that give you extra performance... Precisely by formatting them with a filesystem that doesn't support these sync/blocking Apis.
But I'm not particularly knowledgeable either on this topic, just a (forced) consumer of the operating system with the occasional reading on the side
I find this stuff super fun to learn about. My knowledge is far from complete but the more you know, the more pedantic you can be about things like 'virtual memory' and the misnomer of setting the min/max page file to 1.5*RAM (was used to ensure full memory dumps, not for performance).
If you want to know more, grab the book Windows Internals.
Windows has an extensible model. It's a different approach from most (all?) other OSes. It offers a different set of features.
Sure, AV could perhaps be done in a different manner that would be more effective/faster, I can't comment on that as I lack the insight required -- only MSFTies that work on kernel code could respond in any authoritative way.