Bots can analyze several thousand flight options (which even the sim does) in a few seconds. So odds are it catches a deal someone might otherwise miss.
Also, because BonBook searches direct w/ airlines, it sees inventory not shared with Google (and regularly has better fares).
A system called GDS (Global Distribution System) was built in the 60s as a data transmission standard. Was used by airlines to publish fares (among other things). But it was complicated so aggregators (Sabre, Amadeus, Travelport) were born to ingest all this published data and make it easily searchable.
When travel went online in the late 90s, Online Travel Agents (OTAs) were using this data, and since then most new OTAs have too. (An example; Expedia's first patent minimized GDS searches per customer request, saving them $$).
But, because OTAs take a cut and airline margins are thin, IATA (group of airlines) came up with a new system called NDS (New Distrubution Standard) in mid 2010s. Since its an XML standard that anyone can consume direct, airlines have been trying to push everyone onto NDC by simply not publishing certain tickets via GDS, requiring OTAs to book X% of tickets via NDC and even removing inventory entirely.
Some examples: American trying to go full NDC recently but getting pushback and Turkish Airlines pulling out of Sabre.