I would ask ‘what are you signaling if you don’t get your own domain?’
If it is signaling that you can’t afford $10 a year you are signaling cheapness which is not an appealing or desirable attribute.
Medium at first used the power of branding to insinuate it was a place that was a little better than other blogs. Gradually it became known as something that is a little worse.
I remember talking to some guy who was amazed that he’d gotten 78 views on an article and I didn’t have the heart to break it to him that it would take more like 250,000 views to impress me.
You know the ‘eternal september’? Like it or not some people work a lot harder than other people (how does Casanova bed so many women?) or are a lot smarter or have much more interesting insights.
Being on Medium or LinkedIn or other sites lowers people’s perception of you because you get linked to particular styles of discourse that come across as disingenous even when you are sincere.