Let's try to enumerate
1. Data integrity based on blockchain protocol. Ok, there is. The scope is rather narrow.
This was already covered before bitcoin, distributed databases have existed for years, are tested material, are already in use at a giant scale, Cassandra is one year older than bitcoin for example, far more used than any other blockchain projects and am I seeing Amazon trashing SimpleDB for ..tron? or solana? Lol.
Visa is doing just fine and it's highly unlikely we will ever need trillion of transactions between accounts a day, not with this world population.
For a private company or for a government a distributed public database is really not something that attractive, as I'm pretty sure not that many bitcoin fans would like to see all Visa transactions published online, even if it's only their card number and not their full name in the that.
Exactly, there was no real need for them in the first place. Did they make a lot of money and had a ton of customers, yeah, fidget spinner sellers did the same, but that doesn't mean it will go on forever with the same cash inflow. None of them has done the magical things it was supposed to create or at least fix, and what's actually sad is that the main purpose of Bitcoin and its strong point is starting to be demoted outside the podium when it comes to the purpose of using it.