Hard to say. One would have to know a lot more about 19th century books on usage than I do in order to determine whether "the more" was perceived at the time as being supplanted (and there was an effort to preserve its use). But 'the more' has long been in natural use with the comparative.
Just FYI, though, "more better" is pretty frequently used ironically these days by the hipsters and the whatnot to simply mean "better". Also, while I think no one would responsibly advocate this use, I think you could make an argument for saying "peaches are more better than apricots than plums are better than pluots".
To use the correct adjective with the phrase "in detail", think about fewer vs less in number vs amount - but remember "in detail" means specifically or completely already. Examples: I have read your question and answered it "in detail". If you want to read my explanations "in more detail", keep reading. You might find another answer that explains it just as well with fewer details (which ...
phrase usage - "in more details" or "in detail" - English Language ...
The only example that comes to my mind that follows the pattern "the more the + comparative degree" is, "The more, the merrier." But that has a very different usage than what you're looking for.
adjectives - The more + the + comparative degree - English Language ...
Sure enough, this ngram shows that stupider got started long after more stupid. Apparently, the need to compare levels of stupidity was so great that people granted stupid a sort of honorary Anglo-Saxon status in order to use the more-convenient comparative -er.