Apple seems to be facing more difficulty than usual in getting its latest range of iPhones into customer hands than usual in 2021. The latest report on the subject indicate that the supply issues in question are likely to ease off - albeit not for several months from now. In the meantime, hopeful buyers are still likely to endure relatively lengthy waits until their new flagship gets to them.
https://www.notebookcheck.net/Apple-s-iPhone-13-series-stock-woes-are-now-slated-to-persist-into-2022.578111.0.html
I bought a pro max 13 1tb from apple in china and it took over a month to receive it.