I have a 2080ti an i9-990K 32GB of Ram at 3000 and a 1TB m.2 nvme drive. It takes longer then 15 seconds to lauch the sim and get to the main menu and more then 15 seconds to load into the Sim.
I’ve never timed it myself, but it does for me as well. And probably always has done. It’s a little more complicated than Word, so does have to load/check a lot of things.
For example, if you have a lot of mods in your Community folder, this can increase the load times too.
The sim does nothing for about 28 seconds from the moment the icon is clicked to when the loading screen is shown.
From clicking the icon to the main menu it takes about 145 seconds here, about 20 seconds less if fastlaunch is used. SSD installation and nothing in the community folder.
The whole sim loading process is a bit amateurish to be a Microsoft product.