The block editor is a slower to build anything in. It’s far more steps, dozens of more clicks, and requires more time to learn for novice users, and requires training for anyone not experienced with using it.

If you can use Word, you can use the classic editor. Its learning curve is tiny.

Many… of the largest WordPress sites use the classic editor. Every non-profit I’ve worked with uses the classic editor. 2 of the nation’s largest banks use it as well.

All for the same reason, it’s easy to use.