There are things governments cannot do that private companies can: shut down and go away because you made product no one wants. Over time this applies a positive pressure on governments to accumulate junk - layoffs are unacceptable, costly, etc. It isn’t the ‘fault’ of government. It’s just that cleansing is necessary for quality And systems that do not allow for cleansing have junk perpetuate.

Governments cannot discriminate, which is the fastest way to trial product - targeting your most fertile customers and adapting. Therefore, they will be locked into massive waterfall-style design.

Governments cannot ignore edge-cases.

It makes it really hard, though I’ve noticed that lots of new gov.uk stuff and things like Id.gov are pretty good.