I'm pretty sure wood framed apartments, new housing developments, and wood framed commercial buildings use the vast majority of the lumber in the USA. I doubt the lumber market would change much if every single DIYer and homeowner stopped doing any projects for a year.
I will be 50 years old in a few weeks. The longer I wait the less time I have to use my new garage. Also, every year your body gets weaker as you age. For someone in their 30s or early 40s waiting a year or two is not going to have as much impact on them. If you still have 30 or 40 years of time to enjoy your garage shaving a year or two from that is not a big deal. At 50 years old I have 20 years until age 70. How much will I be able to do by age 70? My father is 75 years old and has serious hip problems so he can't do as much these days.
Finally, with my luck lumber will cost even more in 2023 or 2024 if I wait. Lumber futures are right around $1,200 now and forecasted to be just over $1,400 by the end of the year. Forecasts can be absolutely be wrong and lumber futures could end up falling.