Leveling new characters from scratch is time-intensive, but it can be a good side project.
Ultimately, whatever gets you playing the quickest is the right decision. Starting over isn't a big deal—it just requires a little extra time. Leveling new characters from scratch is time-intensive, but it can be a good side project. What's more, most hardcore WoW players don't just play as one class—we both have several max-level characters on rotation as each brings their own flavor to combat. Depending on the version of the Shadowlands expansion you buy in modern WoW, you may get one character boosted to level 50 for free to give you a leg up when starting fresh.