Standard search features, for example the start menu of Windows have so severe bugs and shortcomings, that I am not sure they get anything right and would not trust them with lower und upper case either. For example type too early in the start menu, and you might just find nothing, after which it might search online. If you delete the text and type again, suddenly it finds stuff... critical race right there. Or how it finds something, when one types the first 3 letters that match, but when typing the fourth letter, the search result disappears...
People make searches so broken, it makes me think they have no idea what they are doing. The bigger the company, the worse the search usually is. I think it is maybe a result of non-tech companies hiring silly contractors, who do half-assed work, hoping that people will be so happy, that they get another contract later. Their customers are not the users, but the company that hired them. In case of MS it is probably ... hm, idk, sheer incompetence, I guess.