This is such a strange take to me.
I was on the broader fediverse for a year or so before lemmy took off, and I got used to the very strong left leaning environment I found there, where compassion for your impact on the people around you was built in to the norms of many of the communities. I wasn't used to it, but I was so glad to have found it.
And then lemmy happened. And unlike the rest of the fediverse, which was largely populated by people escaping twitter because it had been taken over by a fascist, the lemmy population was largely people escaping reddit because they could no longer use 3rd party apps. And the difference in ideology between those two groups is night and day.
To me, the broader fediverse feels left wing and comfortable. Lemmy feels centrist, where half of my time as an admin is banning trolls and bigots spreading hate.
tl;dr - Your definition of leftist is not my definition of leftist.