Those were all done with private money(to make the profit you know about) and didn't matter when they failed. Success in such ventures was rare then, and is rare now because they still happen. The difference is that there are more of us(nearly six times as many as 200 years ago) with higher expectations and requirements. There are very good reasons why we no longer allow landowners to carve transport across their land, or build factories wherever they want.
Trying to force an outdated, inefficient, outrageously expensive 'technology' like HS2 to solve a problem that doesn't exist is not 'taking a risk'. At best it is backward looking, and at worst inept, ignorant and incompetent.
Yes, most were as the Government of the day had no thought or conception of "Nationalisation". With just one exception I will refer to, the 1858 Government contract for the building of a sewer system for London, the majority of the rest were built due to private enterprise, a desire to build a better future, along with, yes, the life long temptation a man, corruption, like George Hudson and his railway 'empire'.
But in the end the canal building, then the likes of the Manchester to Liverpool Railway, along with all the other major lines built, pushed the country's economy from one based on agriculture to a booming, World beating, industrial society, creating thousands of jobs (yes, there WAS a downside to that from a social point of view). The gas and electric industry grew across the country by way of private investment and the usual potential of the essential "Profit". But all this, and so much more, developed due to government allowing and encouraging private enterprise to build the country's infrastructure fit for the next century. A
highly successful approach, with of course some failures being propped up by public funds., but overall Britain profiting from it all.
That is what should be the case now; let private enterprise take on infrastructure projects, seeking out potential benefits, as they do every day in the industrial and civil world in the UK, taking the risks, but enjoying the profits. That way 'budget' and 'completion' over-runs will be their sand the investor problem, not the British taxpayer. Efficiency and commercial common sense will then prevail, unlike with the financially controversial HS2/3/4. I am a Conservative who believes in private commercial power, but somehow Conservative Governments have got themselves bogged down in a "Nationalised" civil project. Not good!!
Just imagine what Labour will do, if they were ever to get into power anytime soon, as normally Nationalisation is their field of interest?!