It's important to add the context that whenever our government tries to do something by themselves it ends up late and severely over budget.
So you have to weigh the risks of outsourcing to the risk of the whole thing becoming very late and very expensive. The risks around outsourcing are something further down the line, the risks of everything becoming expensive and late are something that will give the responsible politician a headache now.
Expat/kennismigrant here - it's same "ends up late and over budget" for literally every country (and private businesses).
What Dutch government/politicians seems to be "ahead" compared to other countries - is combination of narrow or short sightedness and (over)correction trough rules, laws and regulations.
Like giving subsidies and tax breaks for electrical cars, rooftop solar panels and mandating household switch from gas (LPG and such) to electric heating and cooking. And ignoring industry professionals for decades saying the distribution network won't scale.
More of the same with stuff like 30% tax rule for expats, which was originally introduced as cost saving measures because actually doing bookkeeping for expatriate expenses was costing government more money. But then more recently expat tax breaks have been reduced and phased out "because cost saving". Meanwhile employers have trouble finding highly skilled workers. And we're limiting numbers of foreign students in universities (by forcing them to do it in Dutch instead of English).
Some Bulgarians cheated/defrauded Dutch tax returns or such - and "solution" was ML/AI reviewing things - but it turned out to be broken/biased and (ab)used for other things - leading to the whole toeslag scandal and government resigning.
Same for nitrogen vs lack of housing... And many more.
Outsourced stuff is late and expensive too, just not directly the responsibility of the minister or secretary of state because of the magic piece of paper in between.
IT is hardly something we need to do occasionally, so build up a department that can do it (not just write up huge reports about what it should do and outsource, like Logius) and invest in the people that will work there (retaining them as much as possible). Give a big middle finger to consultants, and listen to the tech experts. Build boring stuff that works instead of a new app every month.
It's not impossible in theory, and cheaper in the long run. It's impossible because asshats who would actually benefit from left and centre politics keep voting right-wing parties in to power.
I work (and always has) in the private sector and we can be even better at ending up over budget and be even later at delivery. I don’t believe for a moment that the government has a monopoly on underachieving!