This question is especially for people who have joined in the last week. Have you used other fediverse platforms or is this your first time really using one? What do you think of it so far? Are you aware that you can comment on Lemmy posts with a Mastodon account?
I made a Mastodon account a while back after the Twitter nonsense and have used it somewhat, but not as much as say Twitter itself because most of the people I follow haven't joined. And therein lies one of the key problems with this or any Reddit alternative, if people don't join, it won't work. You need users and content both, you can't do it with just one or the other.
I also made a separate Lemmy account as I didn't realize I could use the same for all 3, but oh well. I kind of like having separate accounts for them as that makes more sense to me in my head.
I think I agree here - I can't easily use my mastodon account on lemmy without also having the mastodon UI, which doesn't work well for lemmy and vice versa. So for now, one account per service type.