Rvest works fine with tabular data. If, however, you are working with data outside of Wikipedia, you will find that website data is very rarely available in a <table> and is instead part of a hierarchical tree, which is a pain to process/clean in R.
In such cases, working with Python/BeautifulSoup4 and importing the clean and normalized data into R will save frustration over time, even offsetting the overhead of using two languages.