Trying to traverse the web landscape and/or getting out of one's comfort zone is of course a very valid incentive. But if one wants to "transforms a small Python utility" by "turning it into a web application", I believe more efficient paths could be tried.

Streamlit is not mentioned in the article, yet I can argue that is unbeatable and that by a large margin in how quick it is to get from a Python script to a decent, functioning web application.

In general, going one-language, full-stack (Vaadin, Streamlit etc..) is probably the right path for anyone who doesn't want do front-end but has to. IMHO of course.