This topic is now 109 posts long and I believe it should be considered as a mega-topic risk.
Despite there bring some new talking points (OptIn alternative), I suspect this topic is too long to support valuable discussion. Newer ideas like OptIn scopes can be discussed better elsewhere where the topic is not flooded with positioning for/against package-private by new readers.
This topic receives a lot of traffic and it’s a hotspot for those coming from Java to post their position without adding anything new. The longer this post means it’s not practical for new readers to go over what’s already been discussed.
There may be more discussion to have here in the future so it’s hard to say it should be closed. Ideally those new discussions would be able to start fresh and focused instead of carrying the baggage of this topic.
Here’s the full explanation of Mega-topics (Please close the mega topics)