No, long term, web apps are more expensive because the front end needs to be completely re-written ever few years. A desktop app written in Qt can be kept running for a decade with very little work. (This assumes no Qt library upgrades, which for in-house apps, are most unnecessary.)
The primary advantage of web apps is "zero install", which is a major point of friction at large corps.
> ...needs to be completely re-written ever few years.
No it doesn't, the HTML spec hasn't changed, whereas QT has. The issue is how the webapps were built in the first place. You don't need Nextjs and all it's friends to post a form to a backend once an hour but somehow that is becoming the standard approach...
The primary advantage of web apps is "zero install", which is a major point of friction at large corps.