It's a mess in the US because Turbotax and others make money on that complexity and do lobbying to keep it that way.
I remember when I lived in the US a few years ago. Everybody told me that I had to go through a professional to fill my tax return as it was just too hard and error-prone. It sounded insane considering my situation was extremely simple. I was also surprised because I assumed the American tax system to be simpler than the French one.
In the end, it wasn't that hard, but I did have to spend some time to find and read the proper documentations. I think in France people are more reluctant to spend money on things they can do themselves, where Americans are more willing to rely on service providers.
All for about $60.
You know what would be worse than that? A system which has absolutely no competition or financial incentive to improve....
The majority of UK residents don't need to file a tax return. The correct tax/national insurance/student loan deductions are withheld from their paycheques, and in case of problems, a phone call will normally sort them out.
Some people need to file returns. (Those that don't need to can also choose to.) Those people that do can file on paper, though the Government website, or using third party software. There's around 30 listed software providers for personal tax.
The fact most people have never seen a tax return in their lives hasn't prevented competition for tools in the more complex cases.
There is no reason to pay a third party.
There is no reason to get a third party involved in your private financial matters, just another place to get hacked.
And just because it was tolerable for you, doesn't mean that's average. My taxes took four days and about eight pages, and I didn't make much last year.
Again they already know all this shit.
I filed taxes in NZ a few years back and it was a hundred times easier, "next next finish," on a modern website. Took 15 minutes.
Which is odd, because I've used Turbotax (and others) in Canada and it's also been a breeze.
Almost only companies use third-party software here, so the market for tax software is much smaller.