We would like to completely restructure our URLs. At the moment I got the question from IT if it would be harmful for SEO if they just switch all URLs to a new URL (e.g. remove a directory from the URL) without forwarding it via 301. So the URLs would just be replaced in the same page instead of creating a new page and placing a redirect.
It's not an ideal situation overall, but the website architecture needs some work. Question is if this would do harm that would be undoable.
Could anyone give any advice? Thank you so much, really appreciate your time.