Not buying that.
The argument made in TFA isn't that the Swiss method works because of population size or GDP per capita, but because the processes and goals are completely different.
They work backwards from an agreed goal - written into law - that continuous improvement into infrastructure is a requirement of all governments, regardless of political bent. I actually don't think this is controversial, even in the UK, it's why there is now majority support for nationalisation of the railway operators (and water companies, and more) - it effectively forces capital expenditure rather than the decades of capital extraction we've suffered from.
Some of the Swiss projects are simpler because of geography (shorter distances), but some are harder (long tunnels through mountains). GDP per capita is an output, not an input - if we'd started doing this decades ago instead of believing the Regan/Thatcher nonsense we now know just doesn't work long-term, our GDP per capita would have benefited and it would unlikely be a 2x difference.
As a country the UK is so quick to dismiss initiatives from other countries that are shown to work there - from capital investment into infrastructure, to sovereign wealth funds, to encouraging retail investment into stock markets more (compare the US landscape to the UK landscape), to abolishing leaseholds - all because "that won't work here". Yet the data being cited - including by yourself - is not data. It's a hypothesis. Perhaps we should just give it a go, eh? Maybe for 10 years, let's try something different and see if any of it is better than the current baseline? Because it probably will be.
The UK thinks it is special, and in some ways it is, but it is also constantly shooting itself in the foot so that the Duke of Westminster and Duchies of Lancaster and Cornwall can keep making money, and so that the ghost of long-dead prime ministers with nothing to add of value to the 21st century can remain venerated by the political class.
We need to wake the hell up.