At the end of the day that’s a large reason to choose any of the federated platforms because as it matures we will seamlessly be able to communicate with each other. Be it Mastadon, Kbin, Lemmy, Pixelfed etc.
That’s what I love about federation. It won’t matter what platform we are on, we just choose the one that looks the best for us and can talk to EVERYBODY. It wouldn’t surprise me if down the road there is a better universal alternative that shows Mastodon, Lemmy/Kbin, Pixelfed content in their original format all in one instance (could be like tabs or all in one feed). I would personally use that but if anyone just wants to see posts in a Lemmy-like format they have the power to choose.
I heard of mastodon but didn't care because I don't use Twitter or social media in general, really. Lemmy is content aggregation and forum which is more my speed.
Honestly, I don't really care about that feature. I don't care to do "social media," and Mastodon is a part of that (although I DO use Discord with my small D&D/Roll20 group). I do have a Mastodon account that's active but, due to the fact that my wife and I did a WHOLE LOT of IRC back during our college days, we just never got into Myspace/Facebook/et. al. Once we were together for good, there just was never a need and we didn't see the point. My wife is the same way; she's a physics teacher and VERY SMART, but she's just not that into technology (other than gaming). She makes me listen to her 80's hair metal stuff on her Google Nest Hub (I'm more of a Pink Floyd/Tame Impala kind of guy personally) but, other than that, we've just been on Reddit (and Bored Panda for her).
Having said that, I was VERY MUCH into Reddit. It was the closest to "social media" that I was willing to get. I was actually REALLY surprised at what the CEO did; I thought he was smarter than that. I was wrong on this account. I think he is his own worst enemy. They often talk about the "echo chamber" and I think that he's made it his home...