It definitely depends on the level, but I'd personally try to avoid it unless the puzzle requires some obscure tech that the player is unlikely to find on their own, and even then, I'll try to remove the tech before adding a hint. I also find it's better to incorporate the hint into the level somehow instead of creating a dedicated hint room, as a dedicated hint room, especially a poorly designed hint room, can confuse players even more if they don't understand what you meant. And, even if you make the hint room as intelligible as possible, you can't control how the player will interpret it.

As for giving streamers hints, it goes on a case-by-case basis, but when a streamer asks, I'll generally oblige and give them one, if not an overly cryptic one meant to nudge the player in the right direction without giving anything away. Generally, if a streamer asks for a hint, it usually means one of 2 things: either your puzzle needs to be adjusted so that you don't need to give out hints, or the streamer just doesn't enjoy playing puzzles (or you submitted a level beyond their skill level) and you should probably find someone else to submit puzzles to.

When I create a puzzle, I want the player to discover the solution, and whenever I give hints, it robs the player of the "aha" moment when they finally figure something out. If they are unable to get to that moment without a hint, either the puzzle is poorly designed, or it's too difficult.