Minds, gab, and Parler come to mind. There are certainly others.
I've never used Minds and dabbled with Gab when it first came online only to find that it is as noisy and worthless a place to engage as Twitter is, possibly moreso.
fwiw, I thought the same until recently but discovered they are visible with the following format:
Looking at Minds, I already see a big flaw: All posts are under the /newsfeed/ namespace.
So instead of
/username/1234
your posts are here: /newsfeed/1234
I don't think users want to get "robbed" of their posts like this.There also is no embed functionality. For Twitter type shoutouts it is absolutely vital that they can be embedded around the web.
You proved that point