Every system in your firm probably works. The expensive part is the space between them, and it does not appear on any invoice.
Every place data moves from one system to another is a seam. Every seam is somewhere data can disagree, and where a person has to check, correct, or re-key.
Most firms have far more of these than they think, because each one was added to solve a real problem.
Seams do not appear in the technology budget. They appear as staff time and as founder attention on the days something does not reconcile.
That is why firms can cut software spending and feel no relief. The spending was not the cost.
Each system is chosen to be the best at its job. Nobody chooses the set. The result is a collection of individually excellent tools that were never designed to talk to each other.
This is a completely rational process with a bad outcome, which is what makes it hard to notice.
You did not choose a stack. You chose seven products, one at a time, each for good reasons.
Seams do not add. They multiply, because a discrepancy at one seam propagates into everything downstream of it and has to be chased backwards.
Map it once. Every system, every piece of data that moves, and who touches it when it fails. It takes an afternoon and almost nobody has done it.
Then pick the single seam that costs the most and either automate it, eliminate a system, or accept it explicitly and assign it to someone rather than letting it land on whoever notices.
An adequate tool that removes two seams usually beats an excellent tool that adds one. That is not how software gets evaluated, which is why stacks keep growing.