How to speed up firefox loading with old profile?

Question

Mozilla Firefox

I have an old firefox profile. The operating systems change, Windows, Linux, and for each installation I connect the old profile. As a result, on the new system - the fox flies, as soon as I connect the profile - it slows down the real one and a half minutes.
What exactly in the profile can be so slow? Can any file be deleted? Deleting browsing history does not help.
What is important to leave - folders in the links to files in the bookmark toolbar and, if possible, saved passwords. Everything else is not significant. Plugins include uBlock and evernote.

Answer 1

Copy only these files from the old profile (*.sqlite would still be good to use standard sqlite utilities). Or better yet, use Firefox Sync instead of manually transferring profiles.