you dont search inside of reddit. you search for the problem in your search engine and then put reddit after it.

such problems include specific university questions such as a question about Harvard or UC Berkeley or MIT, you won't find any of that on lemmy. questions related to specific cars from a make n model, you won't find any of that on lemmy, questions about professional career fields such as engineering, law, nursing and dentistry, you won't find any of that on lemmy, questions about specific cities and smaller towns or counties that you again, will just not find on lemmy. the only things you can reliably find on lemmy are foss and tech related stuff, some politics although very very left leaning which i personally dont have a problem with, and thats generally about it.

dont get me wrong i love lemmy and deleted my reddit account long time ago but the fact of the matter is that reddit is still one of the largest pools of niche and specific information that you just can not find anywhere else because it is the modern day forums website for practically anything and everything, whether you like it or not.