Previously this timestamping was accredited by notaries. This had the problems of cost and the trust in a notary did not translate well internationally.

Now it is almost free to do and the cost of manipulating a blockchain (if possible at all) far outweighs the potential gain from malice.

I’ve been working with a company that uses a very common blockchain to timestamp documents/artwork/data etc.

It’s a niche use case but it simply couldn’t be done before the existance of blockchains.

It’s really good. So called “dynamic contracts” with hourly pricing known only a day in advance are on the rise. Lots of people whithout access to solar can still benefit strongly this way by timing useage of things like washer/dryers etc. Lots of these devices are also becoming “smart” now to automatically pick a good pricing window.