Loading time differs and increases based on your total SV files to load and write, each time at login/reloadui/zone change with loading screen.
Loading time decreases if you use a SSD, and a fast CPU, and your network speed is stable and fast (uplaod especially).
Loading time increases the bigger your SV files will get during game play.
So disable addons you do not need to write SV data each time, and only enable them if needed (Crafting addons e.g., or Master Merchant and other hungry addons).
Clear library data like /SavedVariables/LibDebugLogger.lua via the slah command, logout and manually delete it, or use DebugLogViewer UI's settings menu to clear it.
Same relates to other addons: Check their settings for "SV clear" options or logout, backup and manually clear them if not needed anymore (e.g. check for unused character names and Ids in the SV files and remove them).
This was answered so many times btw, please use the forum search (
https://www.esoui.com/forums/search.php -> "SavedVariables time" e.g.) or read the ESOUI Wiki, it tells you the same, thank you.
If you already disabled the addons and shrinked the files, you can only logout in uncrowded areas as this will also speed up login loading next time.
Crowded areas need more server inetractions and thus the loading speed will be longer than others (sometimes your house will be fastest to load e.g. , sometimes it isn't... Depends on ZOs magic).