is said in webpage: the pentagram symbol is hard to distinguish at smaller typographicl sizes

So they touch upon it on their site:

The pentagram icon is the original symbol for the fediverse, created back in 2018 by Dr. Quadragon and Eukombos. It’s a great depiction of the decentralised nature of the fediverse, and has been serving the community well. However, its design is a little too complex to be used at small sizes, as you would in text or in a button. It’s also only available in image form, not as a typographical character.

I think they have a valid point. Currently on my website I use a Mastodon logo next to email and git and all that jazz. It's not ideal, as it's not so important that I'm on Mastodon specifically (and I might move to a self-hosted #Seppo instance in the future), but the existing fediverse icon would not work well at that scale.

It's a huge branding effort to make it catch on though. And part of me likes the pentagram better.

My guess is because it's unicode. But that doesn't really matter. How often are you going to want to put the icon instead of just typing the fediverse

my friend, please read the article. it does a great job of explaining the why. it only takes a minute to read.

Not so widely adopted if most results don't include it.