*Sync for Lemmy* is coming out in a few weeks. Jerboa for Lemmy is quite similar to RiF. Memmy for Lemmy is heavily inspired by *Apollo* and is being developed insanely fast. If you're upset about third party apps, now's the time to switch to Lemmy; it will improve even faster with more users and contributors cuz of its open source nature.
I don't think it warrants another new video entirely, but there's one thing I want to somewhat correct from the video. I mention that what instance you join doesn't matter much. This is still mostly true, as making a new account isn't that difficult. However, it is worth noting that certain instances can decide to de-federate from one another. In practice this means one instance can say hey, I don't want to communicate with you anymore (from my understanding). For example beehaw.org has decided to de-federate from sh.itjust.works, and lemmy.world over moderation concerns. So if you joined beehaw.org, you wouldn't see posts from those instances, and those instances wouldn't see posts from beehaw. So it may still be in your best interest to join an instance that suites you. For example if you're say, a Star Trek fan who primarily used Reddit for that, then it makes sense to simply join Startrek.website. All of the main Trek subs are local to there. Or if you're a Warframe fan, dormi.zone. And the list goes on, there's many instances for many things. TL;DR, what instance you join DOES matter a bit, because it can decide to defederate from other instances, so you probably want to find one that has a theme that matches what you want from Lemmy.
IMO for this reason alone, Lemmy and others alike will never be mainstream. Way too confusing on initial setup, and then no guarantee that you will even have access to all content.
I believe Mastodon can see Lemmy posts and vice versa, but I believe Mastodon uses its own instance, so you couldn't log on to tchncs with a Mastodon account, you'd need to make a new one.