Medium.com is absolutely rotten for this behaviour.
Not only putting the soft, “sign in to view” but then on some articles requiring a full hard paywall… But you only know this after signing in.
I’m not entirely against charging for well written articles; good writers deserve compensation, but don’t tease me, make me jump through a hoop only to find there’s another much higher hoop sitting beyond it.
I have no idea. But my gripe is the lack of a clear notice that “this is a paid article and you must be paid member to view it”, it just says words to the effect “sign in to view”.