I agreed, I like these patterns but I never encourage anyone to start with these patterns, First build a simple monolith to handle the situation, if there is a hard problem then and only then these should be applied, But these days I am seeing quite opposite though, I don't see enough evidence to start with these patterns and always use them as rule of thumb .

There's no question that it adds complexity, but I wouldn't agree that it adds a "huge amount." The Saga Pattern is actually very straightforward.

But as with anything, the question is "is this complexity worth the price you pay for it?" For me, given the advantages that microservices offer in many contexts, I find that using the Saga Pattern to maintain consistent state is totally worth it. But that won't be true for everybody in every situation.

Any library/SDK that allows you to implement these patterns should have sufficient testing scaffolding available as well. We use MassTransit for a large, distributed .NET Core + RabbitMQ service layer and unit tests are no more trouble than they usually are with the build in Bus and Consumer test harnesses.

If you build your system around events then the saga pattern doesn't take much additional effort.