Sure but if you let the government do it you can be 100 % sure it will be the worst software ever designed.
They have no incentive to make it good. You know the drill.
Taxes in Norway are a breeze, for example. You can design services so that they are easy to use for the taxpayer.
If you want a more local example, take a look at the Indiana DMV (Department of Motor Vehicles). The upgrades took it from "Ugh" to "maybe I can do it online or take a quick trip into a branch". It might have degraded in the last 10 years (i moved away) but I didn't mind dealing with them. Getting an apostille (special stamp for international stuff) on a document wasn't bad either - you just needed to be patient and wait on mail.
Taxes can be like this.
And I'll mention that the government - and you - have incentive for this. Taxes that are easy to pay and easy to fill out for the average person means that there is greater compliance. Greater compliance means more revenue, and we can spend the time and money on other things (like auditing complicated taxes instead of people using a 1040EZ)
Doing your taxes via self assessment is free and takes about 30mins to an hour online via HMRC.
Most people also go their entire lives without "doing their taxes"
It’s not like I’m not aware of bad software by government but the taxes ain’t it. Possibly because they are, in fact, incentivised to make it good.
And yet I regularly come across companies that manage to do even worse, despite having insentives. What should happen to them, Execution?
I expect the quality of government websites to improve exponentially as the old guard takes their "series of tubes" mentality out the door with them.
The purely online based one now is very decent.
They then mandated you use a third party to file things like employee payments saying there would be free or cheap software to do this and listed a few.
Over time the free or low cost became more and more costly for something you have to submit to them by law.
It is a difficult issue as most of the government IT are straight up incompetent. (Just last week they gave up on a project after spending $2 Billion AUD).
The private industry would likely do a better job but then some people get rich, as opposed to a whole bunch more getting paid for what ends up in the bin.