"highest level of popularity" is grammatically correct and commonly used in written English.
It can be used to describe something or someone that is extremely popular, or to compare the popularity of different things. Example: "The band's latest album reached the highest level of popularity, selling millions of copies within the first week of its release." In this sentence, "highest level of popularity" is used to describe the extreme popularity of the band's album.
— Before the shutdown, Trump's wall proposal reached its highest level of popularity in the December Quinnipiac University National Poll and it was still unpopular.
In their more than 100 films together, spanning three decades (1921-51), Stan Laurel and Oliver Hardy's impeccably constructed comic mayhem carried them to the highest level of popularity and a fame that easily crossed international borders.
A row over migration has broken out in the top ranks of Germany's resurgent Green party as a poll showed that it had achieved its highest level of popularity in seven years.
The elite series had also arrived at Indianapolis just as Nascar had grown to its highest level of popularity and represented a truly American form of racing, with almost no foreign drivers.
There are valid reasons why the nominations took the form they did; in particular, that they tend to honour artists who have achieved the highest levels of popularity and that there are no individual awards for specific genres.
While Fatah's Abbas enjoys a high level of popularity in the Palestinian territories, he is not in control of the Gaza strip.
The character has achieved a high level of popularity in Japan, but the English-language media reception has been more mixed.
Surveys show a high level of popularity with our clients, especially for early evening appointments, and high acceptance levels from our radiographers and assistant practitioners.
Young women's criticism of sugar daddy relationships suggests that, had they possessed other means of accessing the items of exchange that they acquired through transactional sex, the practice would not have enjoyed the high level of popularity that it did.
