They index WARC archives and can be used to quickly find records. You can build on top of this (and some systems do) to make a proper search front-end.

But in general, these archives are NOT geared towards full-blown search because it would be pretty expensive to keep the indexes in hot cache. Plus you would need to deal with historical versions of records, which is not normally done in search UX.

[1] https://wiki.archiveteam.org/index.php/The_WARC_Ecosystem#CD...