Good question. I've never thought about it because I've been syncing my phones with my laptops for years. Here's the answer from [https://www.google.com/search?q=How+to+export+firefox+bookmarks+on+Android&client=firefox-b-1-d&sca_esv=0cfb0ff3a5db7a01&ei=G9_NZ-GkC_vk5NoP_qjOoQQ&ved=0ahUKEwihntLM0f2LAxV7MlkFHX6UM0QQ4dUDCBA&uact=5&oq=How+to+export+firefox+bookmarks+on+Android&gs_lp=Egxnd3Mtd2l6LXNlcnAiKkhvdyB0byBleHBvcnQgZmlyZWZveCBib29rbWFya3Mgb24gQW5kcm9pZDIEEAAYHjILEAAYgAQYhgMYigUyCxAAGIAEGIYDGIoFMgUQABjvBTIFEAAY7wUyCBAAGIAEGKIESN8hUNEKWMgYcAF4AZABAJgBVKAB9QOqAQE4uAEDyAEA-AEBmAIJoAKWBMICChAAGLADGNYEGEfCAgcQABiABBgNwgIGEAAYBxgemAMAiAYBkAYIkgcBOaAHrCs&sclient=gws-wiz-serp AI]...

'''FYI... SYNC IS NOT A DATA BACKUP SERVICE''' Sync info... https://support.mozilla.org/en-US/kb/how-do-i-set-sync-my-computer https://support.mozilla.org/en-US/kb/how-do-i-choose-what-information-sync-firefox https://www.mozilla.org/en-US/firefox/features/sync/ https://hacks.mozilla.org/2018/11/firefox-sync-privacy/ '''Sync is not a backup tool but it is a good sync/transfer/move tool''' https://support.mozilla.org/en-US/forums/contributors/707681

Either Firefox want to give their users the possibility to export bookmarks, or they force users to put their bookmarks on the internet, and forcing users to put their bookmarks on the internet is evil. Never the less, the choice is simple, and all boils down to "what is Firefox choice"?