If you've only come out of your cave recently then ever since the early part of 2020 the supply chain for everything bicycle and most everything else is been disrupted. Inventories are low or non-existent everywhere. We are looking at mid-2022 or later for things to get more normal again. Unless some other catastrophe happens in the meantime.
As for spare parts for your shifters and such, many have long considered them a consumable item and when it breaks, you get another.