> I get that blockchain tech is an industry nowadays but from my outside perspective 99% of it and the applications they promote seem rather, for the lack of a better word, self serving

Blockchain might have been as exciting as the internet at the start, but it has turned bad (i.e. been exploited for profit by big corporations at the user's expense) much more quickly. In my view it is because blockchain puts money before technology rather than the other way around, i.e. during the dot-com era it was often "let's just build something useful and worry about monetisation later" whereas with blockchain it is more "we've got the monetisation in place and we'll worry about actual use cases for the technology and mass user adoption later".