[ilian]

For a simple solution, saving the web pages and bookmarks as plain files you can try https://www.tagspaces.org/products/webclipper/

Having my saved web pages as plain files, gives me countless possibilities in terms of portability of my collection... This way I am independent of any online service or product...

[mackrevinack]

even simpler browser extension to download a page as a markdown file:

https://github.com/deathau/markdownload