Take the Vienna page as an example. In the introductory paragraphs, we have the text below. While it isn't incorrect or false, it's quite obviously included only facts that portray the city in the best possible light. If the purpose of an encyclopedia is to present information in a neutral, objective way, this doesn't seem to fit the bill.
I say this as someone who likes Vienna and thinks the quality-of-life studies are correct. But this information belongs in a sub-header, not in the introduction of the article.
https://en.wikipedia.org/wiki/Vienna
Vienna is known for its high quality of life. In a 2005 study of 127 world cities, the Economist Intelligence Unit ranked the city first (in a tie with Vancouver and San Francisco) for the world's most liveable cities. Between 2011 and 2015, Vienna was ranked second, behind Melbourne.[20][21][22][23][24] In 2018, it replaced Melbourne as the number one spot.[25] For ten consecutive years (2009–2019), the human-resource-consulting firm Mercer ranked Vienna first in its annual "Quality of Living" survey of hundreds of cities around the world.[26][27][28][29][30][31][32][33] Monocle's 2015 "Quality of Life Survey" ranked Vienna second on a list of the top 25 cities in the world "to make a base within."[34][35][36][37][38]
The UN-Habitat classified Vienna as the most prosperous city in the world in 2012/2013.[39] The city was ranked 1st globally for its culture of innovation in 2007 and 2008, and sixth globally (out of 256 cities) in the 2014 Innovation Cities Index, which analyzed 162 indicators in covering three areas: culture, infrastructure, and markets.[40][41][42] Vienna regularly hosts urban planning conferences and is often used as a case study by urban planners.[43]
Between 2005 and 2010, Vienna was the world's number-one destination for international congresses and conventions.[44] It attracts over 6.8 million tourists a year.