I'm co-founder of an end-to-end testing product, but I don't actually agree that better end-to-end testing coverage means you should create less unit tests. The reason why is because there's a class of things you want to test that are much better served at the unit testing level. Unit tests are always going to be faster to execute and by definition have a much smaller scope, which is helpful in reasoning about what you're testing.

Our product is really focused on making end-to-end tests much easier to create and maintain. Here's an example video I recorded yesterday of automating Monday.com's sign-up flow using our product: https://www.loom.com/share/1336a5bfa9f54f2190269961991802b5 - looking at this I don't really see what unit tests this would replace, rather I think it gives coverage for things that you'd often have no automated coverage for - i.e. the interplay between disparate components along with interacting with email - basically the steps that form a complete workflow from the user's perspective.