The point here is to not bump the issue. My GitHub notifications are a mess, and bumps cause me to unsub from notifications to issues in my own repository. There’s also a 0% chance a bump is going to cause me to reallocate my evening, so it doesn’t help get the issue moved forward.
Bumping doesn't necessarily mean "sending an email to the maintainer and everyone on the issue", adding a reaction can also "bump" an issue in the sense that it bumps it to the top of the list if sorted by "thumbs up reaction".
