I don't understand how `serious professionals` continue to try to trash WordPress using superficial and often uneducated arguments, completely ignoring the fact that it has huge flexibility, a rich ecosystem, many options for using modern development practices and 40%+ global market share.
I worked in exclusively WordPress for many years. "Flexibility" doesn't mean jack if it doesn't adhere to modern development practices itself. "Many options," yes but the core is just cobbled together by amateurs. It has nothing to do with modern PHP development practices; it's basically just a collection of functions. It doesn't use composer; most of the development stacks I've seen are tricks to basically gut its dependency management and rewrite it themselves.
As for a "rich ecosystem" and "40%+ global market share" — popularity has nothing to do with quality.