After trying many of the options for upgrading antiquated laptops, I have come to the conclusion that the best approach, next to not bothering to do it at all all, is to use Cloudready to “make” them into a Chromebook. That's what schools use that can’t afford upgrading their old Microsoft Windows laptops
The Chromebook will handle very nearly everything you want to do, and formerly did with Windows, but using Google Docs, unless you're writing a book and prefer to use Word. (Word itself can indeed be used online on Chromebooks, costs $$)
If Word is not your cup of tea, you do need a Microsoft or Apple device to organize many notes and resources with advanced software like Scrivener. The cheapest of Windows 10 devices will do for that purpose.
I hated Word when I was publishing my two books. Light years ahead of Word is Scrivener is (Tap or click for) Scrivener for iPad,
Or just tap or click for a free book on Scrivener.
Tap or click for Cloudready. Free to individuals.
However, if you need to work offline, Linux might also be preferable, though you can indeed work offline with a Chromebook.
For the diehards who want Linux, it is no big deal to create flash drives for Zorin Lite or Linux Lite. They either work or they don't.
If you really want Linux, consider a PineBook for under $100 that looks for all the world like a MacBook. Not the fastest, but not the slowest either.
In contrast to earlier awkward laptops, a PineBook really does work well on the lap, being extremely lightweight And well-balanced.
Both an old Vista turned ChromeBook laptop and the PineBook ran YouTube for me. But nothing more demanding.
As I've mentioned before, you can get a great computer in the Amazon Kindle 8 at $55 to Prime customers currently. A new Amazon Kindle 10 has just been announced.