Test started with the current WC version and working backwards.
One result: The WP blocks compatiblity class / helper needs additional functions / methods, including WC_Blocks_Utils::has_block_in_page, because WC is using it for the REST API.
This happens when accessing the WooCommerce ‘status’ page in the admin area.
Another one being: Frontend works flawlessly.
In the admin area, the WooCommerce “home” page is broken, aka displays just the admin area with everything around, but no content. The settings page works, too.
Starting from v6.9 and below, there were additional errors, probably related to PHP 8.x, which escalates all errors one level further, so a Notice turns into a Warning, and Warning turns into Fatal Errror (or sometimes Deprecated, if one is lucky).
Probably one of the most nonsense “features”, as German “states” (which arent, technically speaking, ‘states’, but ‘Bundesländer’, which is not the same) have absolutely no relevancy for both the order process and the taxation (VAT). German postal addresses do not include the Bundesland, because its not part of the official address. You may add it, but it doesnt help anything. Also, there are no differing VAT per Bundesland - the VAT is applied nationwide.
Where the Bundesland would be relevant is eg. in wage payment, or health insurance, where depending on the Bundesland you live in, there may be slight changes in taxation and how much of your wage is being taken away for health insurance (sth in the lower single percent range). Which I dont see has any relevancy or connection with an online e-commerce solution aka web shop.
I guess this is just another part of Feature Creep.