A lot of domain investors use Google Trends as a way to help research or validate their research on prospective purchases and hand registrations. Google recently released a video that is worth watching.
In addition Roger Montti over at Search Engine Journal did a good breakdown on the data and what is most valuable.
Roger writes:
in my opinion one of the most useful offerings is the ability to explore the topic that’s related to the entity of the search query. Exploring the topic shows the query volume of all the related keywords.
The “explore by topic” tool arguably offers a more accurate idea of how popular a topic is, which is important because Google’s algorithms, machine learning systems, and AI models create representations of content at the sentence, paragraph and document level, representations that correspond to topics. I believe that’s what is one of the things referred to when Googlers talk about Core Topicality Systems.