If your sole goal is different ways of thinking, just studying linguistics in general can be helpful, but not as much as actually immersing yourself deeply in a variety of languages.

The simple fact is that most people have trouble actually internalizing the different ways of thinking if they don't have to use them themselves or spend a lot of time focusing on them.

As a really easy example, the general concept of using kinship terminology preferentially to abstract pronouns (as for example done in Thai and Indonesian) is something that I, as a native English speaker who has studied linguistics extensively can conceptually understand, but I still can't think in that manner without heavily focusing on it. I have similar issues with the concept of measure words from Mandarin Chinese and number forms changing based on what you're counting as in Japanese. These concepts are something I generally understand, but they're sufficiently alien to the way I normally think that I can't effectively utilize them without making a significant effort.

In contrast, I've spent enough time studying Esperanto that I have no issues whatsoever in thinking in the rather terse, highly information dense conceptual framework that the language was built around (which, combined with the number of different languages I've studied at least a little, has lead to me randomly register switching in spoken conversation for single words just to try and express exactly what I mean, much to the consternation and amusement of my friends and family).

Looking at this a bit differently, fluency in a language is just another skill. If everyone used the logic of only learning skills that they needed, very little would get done in the world, and quite a few rather significant inventions may have never been created. You should absolutely learn things that interest you, it will help expand your ways of thinking, and you never know when it will be useful.

I agree. I learned English to read scientific articles and papers, and Japanese to sing anime songs. This merit of changing perspective is more of a bonus than the driving force. I think of driving forces as personal so I don't share them as openly or regard them as helpful to share.

In one month I can learn the grammar of a natural language, but not its cultural intricacies, which make the actual impact. I am more of a generalist when it comes to programming languages, since their cultural intricacies are quite a bit more upfront.