Are Mega Stores Still In The Game?

Are they still in the game?, as i’ve not been able to find one in all the games i’ve played over the past couple of months.
Are there any specific world gen settings that triggers them?

It wold be a nice start to tell us about verrsion of the game you play.
In 0.F2 megastores are not something uncommon, in my experience at least.

Yes, they are. As Ftor wrote, it always help to know what version you’re playing on, as the game changes a lot, and usually does so daily.
But I’ve tested it in build 2021-11-18-1049 and they can still be found:

Time to go shopping...

For this world I’ve used the default terrain settings.
Please note that some mods do change the chance of this (and other) building spawn.