I highly doubt they started on TES 6,
straight after TES 5 (Skyrim) released (2011).
I think it's taking so long,
since they procrastinated working on it for so long...
They where mostly focussed on milking TES through Online and re-releasing TES 5 an obscene amount of times, now they even re-released TES 4 (Oblivion), instead of putting in the time/effort/money for creating a new game.
Working on Starfield also took a chunk of their time, however that game is badly received. What scares me is that on the TES 6 wiki page, they mention that it will be written in the same Creation Engine 2 as Starfield used.
https://wikiless.tiekoetter.com/wiki/The_Elder_Scrolls_VI
The wiki does mention it has been in pre-production since 2018, which still seems doubtful to me.
