January SALES EVERYWHERE but NOT on TSW some of the addons are as old as the hills, and still FULL PRICE.
It's one of the negatives of buying TSW for the Xbox One. PC has almost constant sales between the Steam store and the DTG store. The situation isn't going to change any time soon as the issue is with Microsoft, not DTG. If DTG had their way I'm sure there would be as many sales on console as the PC; You're best off contacting Microsoft and letting them know how you feel. There's a sale on PC right now, up to 65% off: https://store.steampowered.com/dlc/530070/Train_Sim_World_2020/#browse