Automating business: when are smart contracts really useful?

While searching for solutions to automate our contracts, I discovered the world of smart contracts. It turns out that they can be used not only for cryptocurrencies, but also for real business tasks. I found a detailed analysis with specific examples of implementation.
Useful material for a first introduction to the topic can be found here: https://paylinedata.com/blog/smart-contracts Practical cases showing time and cost savings are particularly valuable

Oh, smart contracts are interesting! Where are they already being used in practice, apart from cryptocurrency? For example, are they used in ordinary businesses such as rentals or deliveries? And how difficult is it to implement them?

I'm still figuring it out myself, but from what I've read, smart contracts are already being used in logistics to automate payments upon delivery, in real estate for rentals, and even in insurance to speed up payouts