Do brands really prepay for parts arriving 2 years later? That sounds incorrect. I've heard of +/-90 days of delivery in business generally. Not for long term preorders.
Another detail, from a Bike Retailer article: inventories were low going into the pandemic because retailers didn't want to stock up too much while the tariff was in force. And then inventories got wiped out.
I wrote a thread exploring price spikes from Giant that predate the pandemic. The bike industry was saying in trade rags long before the pandemic that there was a supply crunch around manufacturing parts.