Most of the time gov, orgs and companies don't listen to their in-house engineers but will pay $$$ to some consulting firm, only to confirm the same thing or just to show that "they are taking actions towards the solution".
In some cases there is distrust from management on in-house employees or in some other cases they want to show quick results without distracting their teams from their planned tasks.
Of course there are the cases that managers have personal motives, either to add an extra (useless) achievement on their list or even worse to get referral fee or presents from the external consultancy.
The people working inside the company may be both judge and party to the issue, it’s not always a bad idea to call in consultants. Do you prefer independent and somewhat misinformed or stakeholder to the issue and knowledgeable?
If you can't trust your people, why are they your people? The consultants are going to get the story from your people anyways (even if they do their own data collection, your people are going to tell them where to look), so it's not like you're actually eliminating the bias, you're just obfuscating it.
You hire consultants when obfuscation is the point - it's not Jim from down the hall saying this, its the consultants. Sometimes there are legitimate reasons for obfuscation, but it's always some variation on "so and so needs to hear this, just not from me."
There is a simple expression for that: decision laundering. You use a third party to convey credibility to a decision you have already taken internally. Even CEOs themselves say it in private.
Ah, but by outsourcing the consultancy to AI, the consultancy firms are playing the same game! Now we just need to train a perfectly bureaucratic LLM to provide iron-clad but completely vapid conclusions and citations, and we can finally fire all of those pesky public servants!
That’s a kind of due diligence theater. In particular, managers want to know what their competitors’ engineers would recommend, which is the best static advice consultants say they can give.
What if your in-house engineers are morons but you need to have one particular project done correctly. I don't understand the glorification of normal engineers - quite often they're normal people drawn from normal distribution, with all consequences of that.
Why would you hire, and then knowingly continue to employ, morons? Your employees are not chosen at random, you can evaluate their skills and select the ones optimal for your organization, as demonstrated both by their prior experience and their work performance under your employment.
On the other hand, the people you get from the consulting firm, who were not hired with your particular needs in mind, and who are assigned by leaders who are both unfamiliar with what you do and have motivations which may not be perfectly aligned with yours, are normal people drawn essentially at random from a normal distribution. Maybe you don't need to have a particular skillset in house full time, but the person whose job is to do something will always outperform the person whose job is to maximize billable hours.
This is my experience as well. One of my clients tasked me with stuff their average engineers can't do due to many reasons, not only competency. They just had to have this one project working in time.
Personally consultants are just another tool in the mid-hi management toolbox. Just as a workforce on a payroll, this can be used in a good clever way and this can spiral into a shit show real quick.
If shit hits the fan, the director can pull the "we just followed Deloitte's advice" where "Bob from IT said so" just does not have the same responsability shielding.
In some cases there is distrust from management on in-house employees or in some other cases they want to show quick results without distracting their teams from their planned tasks.
Of course there are the cases that managers have personal motives, either to add an extra (useless) achievement on their list or even worse to get referral fee or presents from the external consultancy.