What makes Endless faster than Ubuntu?

Without measuring it, I noticed that Ubuntu 18.04.1 takes longer to boot. I estimate +10 seconds. I am curious how did you achieve that. I mean both are based on Debian and have the gnome 3 desktop with gdm login, right?

By the way, my laptop is an Acer Aspire A114-31, and both run fine.

I had Endless installed by default, and was satisfied enough with it to use it for half-a-year, but I had to replace it with Ubuntu; because Endless kept pestering me with a password prompt, despite turning off auto-updates; I need many development libraries for next semester, which are easier to install on a traditional distro e.g. “apt install libsfml-dev”; and other tools are also painful or impossible with flatpak.