Agree with the upthread comments that indicate that a higher population France seems quite doable with a France that follows a similar demographic trajectory to the European norm and doesn't go into a low cycle in the 1800s and 1900s. (Though still topping out at less than 230 million!).
You'd also see much more emigration if France kept a more typical demographic trajectory and a much more French United States and probably a number of other New World countries.
On the point of industrialisation, as I understand it, the big early difference between France and Britain, was that France had much higher shares of population in agriculture and lower agricultural productivity per worker.
That is, France actually largely had no major problems keeping pace in science and industrial technology or productivity in industry, but a large share of the French population were in fairly low productivity agriculture until quite late (the early 20th century).
See -
https://ourworldindata.org/employment-in-agriculture
Also lower integration into trade measured by volumes (though France apparently did not have higher tariffs than Britain).
A France that followed both the kind of normative demographic history, and in agricultural productivity and employment, would be a much different culture today. Or at least it seems to me, much of France's distinctive modern day culture and identity is intertwined with combining quite a strong sense of the nation, engagement with ideas of Enlightenment and post-Enlightenment with stress on reason (as a legacy of the French revolution), a fairly secularized fairly laissez-faire attitude to fertility and children, and a quite "backwards" population structure with a relatively large share of population in rural agriculture, more focused on quality produce than productivity and output. (French posters may correct my stereotype).
(In contrast to England certainly, where the population has had a high industrial working class and service sector for a long time and so culture has been quite focused around identities built around this, the culture is not really as much oriented to rural England or food production, and is somewhat skeptical and not as engaged with certain kinds of Enlightenment ideas.)