Yeah, good point. I often find myself wanting to follow what some people are up to (friends or not), and it's always frustrating how it requires you to be a part of a certain platform to do that – you can't follow anyone's instagram, facebook, twitter etc without an account, and even then you still need to go on instagram/facebook/twitter to actually check it out.

I recently created myself a Pixelfed (a federated instagram, basically) and was pleasantly surprised how my profile has a plain, old RSS feed, so that anyone can "track" me without ever visiting a website (which is something that ActivityPub itself also allows, but AP still forces you to be a part of the "system", so to say).

I'd much prefer that kind of Federated world, but I don't see how we can get there in any other way than spreading awareness about it and basically nagging our friends (at the risk of isolating ourselves) – “I wish I could follow your adventures and thoughts, but I don't want a facebook account”. This of course requires a critical mass for basically each person, and probably a way of automatically updating the locked-in platforms (for each post you push to pixelfed/blog it updates your instagram/facebook) so that the ones who take a step out don't need to leave their locked-in friends behind.

How is using ActivityPub any more being part of the system than having to use the RSS 'system'?

ActivityPub requires an account on a server of some sort. RSS is client-only, so the "friction" is much lower.

Of all the people who listen to podcasts through some kind of an app, how many of them have created an account anywhere?

Blogs used to be/are good for that.