"From the beginning of his career in the 1830s, his achievements in English literature were compared to those of Shakespeare."
in his time he was not 'literature', it was pulp, common, 'popular'.
is Stephen King today, 'literature' or just 'pulp fiction'?
this is a subjective thing. authors that are 'popular' sometimes aren't considered 'literature'.
in your very own citation:::
"Among fellow writers, there was a range of opinions on Dickens. Poet laureate, William Wordsworth (1770–1850), thought him a "very talkative, vulgar young person", adding he had not read a line of his work, while novelist George Meredith (1828–1909), found Dickens "intellectually lacking"."
"Henry James denied him a premier position, calling him "the greatest of superficial novelists":
But maybe, it's not population wide.
More people were reading Dickens, so rate of reading in population was increasing. But the elites that thought everything should be in Greek/Latin, thought everyone reading Dickens was a downgrade.
Every generation argument.
Weren't Egyptian hieroglyphs basically emoji's.
The real argument against Dickens at the time was more to do with his habit of serialising his novels in cheap newspapers. This then rendered his subject matter of choice - social commentary, fiscal egalitarianism, and empathy for the poor - a little too accessible for the comfort of the ruling classes.
He did so even in his own Newspaper 'Household Words' - which while championing the cause of the poor and working classes, did so by addressing itself almost exclusively to the middle classes!
"...We seek to bring to innumerable homes, from the stirring world around us, the knowledge of many social wonders, good and evil, that are not calculated to render any of us less ardently persevering in ourselves, less faithful in the progress of mankind, less thankful for the privilege of living in this summer-dawn of time." Charles Dickens
He started this with 'Hard Times' - a thinly veiled socialist critique against unbridled capitalism and immorality. It specifically targeted Edwin Chadwick, who helped design the Malthusian basis of the appalling Poor Law of 1834, but was more generally an attack on the Utilitarians of the time. Shaw described it as a "passionate revolt against the whole industrial order of the modern world".