SEARCH is used by the WebDAV standard, not that I like WebDAV search syntax https://gist.github.com/CarlSchwan/66fde29d52022c0ef76aec362...
That’s probably part of the reason the more general one proposed for HTTP is “QUERY” and not “SEARCH”. Also, WebDAV, in following its apparent design philosophy of “more is more”, has multiple different GET-with-(required or optional)-body methods with different purposes: PROPFIND and REPORT as well as SEARCH.