I've donated >$100 to one streamer in one go, who I've watched for years for both entertainment and game-related education (watching his tutorials on how to get better at games I play).

The traditional sense of paying someone cash for something often happens in parallel: you give something and you immediately get something. I think the mentality (or, at least my mentality) with streamers and tipping is a bit different: after you've received something (e.g. entertainment for X duration), _then_ you give something (a tip). Tipping someone $100 at any point might not make total sense in the moment to someone else observing, but tipping someone $100 for e.g. the last 6 months of free entertainment makes a lot of sense to the tipper. Sure, you could get away with not tipping and make that entertainment truly free, but you also want to support those who are creating it and encourage them to make more. After all, you pay for other entertainment, and often a large tip every once in a while still evens out to (much) less than you'd pay otherwise.

Thanks, this reply definitely helps me understand it a bit more.