Centralization is one, where only a handful of big corporations dominate the internet. The other part is every platform trying to become everything and cornering all markets.
Take social media for example. In the early days, facebook was for connecting with your friends and family. Instagram was for posting and sharing photos. Myspace and twitter were for microblogging. Youtube was for long form videos and vine was for short form.
Now every social media platform wants to be a website, marketplace, payment processor, microblogging, short form video, music streaming, etc. This of course causes them to enshittify.