Could you handwrite a draft of your novel on one of these devices? Sure. Will the text recognition save you time and work? Debatable! I try it out on the Kindle Scribe, reMarkable 2, and Supernote A6X. (Since I wrote this passage out 3 separate times, the handwriting was a little different on each, thus affecting the recognition function so it's not a pure test with a control!)

~ gratuitous footage of me writing for those who enjoy that sort of thing~
accompanied by Alicia de Larrocha playing Mozart Piano Sonata K. 310 in A Minor, Presto!

00:00 Intro
01:37 reMarkable
06:05 Kindle Scribe
08:36 Supernote A6X (in Real Time Recognition mode which I did not state very clearly!)
15:01 Longer document on Scribe
17:12 Longer document on reMarkable (yes I ultimately blurred this, sorry, but accuracy was similar to Scribe)
18:20 Conclusion

Links (I get a little commission on some of these, not all.):
Get $40 off reMarkable: https://tinyurl.com/RM40S
Kindle Scribe, etc: https://tinyurl.com/3y97yxtw
Supernote: https://supernote.com