Personally, I wouldn't go so far as to describe ANY of the above points as "cobblers"! It seems to me that this whole subject (which I find very interesting BTW) is more complex that I for one have previously imagined.
But it's quite true that although by, say, the mid 19th century, railways (more or less as we know them today) already existed, I don't think it's really true to say to say that invention, and more particularly development, had stagnated.
Just staying with the railways example for a moment, as I understand it, it was during the period mid 19th century up until, say, the early 20th century (let's guess at 1910 - by which time all the major UK railways already had their own loco designers, factories, etc), the "fine tuning" (i.e. development) of steam locomotives was in full swing - e.g. the invention of improved valve gear (the key to efficiency, i.e. power output v coal burnt), super heating of boilers, improved draughting and fireboxes, etc, etc, was going "full steam ahead" (sorry about that!).
Such things led to the railways being able to move ever greater loads (people and goods) over greater distances at higher speeds with lower overall costs - and that technology, the leading edge technology of the day - was exported all over the world.
E.Gs; who built the first ever steam railway in Germany in the mid 19th century? Answer, UK.
Where was loco super heating and compounding invented/first applied to locos? France (I think).
And let's also not forget please that the creation of a single nation Germany (again, just for example) was only finally accomplished just before the end of the 19th century. Ditto Italy, as just another example.
I suspect that in reality, although it may have been at a slower pace than the internet and modern comms allow us today, both invention and development/improvement (of existing inventions) was taking place all over the world, with "competition" spurring everyone on.
In fact I'm not at all sure that I buy into the idea of a stagnation period in the latter part of the 19th century in any of the developed countries at all!
Interesting discussion though - and harking back to an earlier thread somewhere here about ship building in Belfast, something that should, IMO, be incorporated into both education and political thinking today.
AES