A public beta period is for receiving feedback from developers and customers.
Beta is not an excuse for shoddy workmanship. Beta is to figure out the last outstanding issues and bugs before shipping to production, not to hastily fix a ton of obvious issues, or to redraw icons
macOS Sequoia was released Monday September 16, 2024. The likely release date of macOS Tahoe is Monday September 15, 2025. That's only 20 days from now. Those icons have already been redesigned in Tahoe. What do you expect to happen in the next 20 days? There will maybe be one final beta.
Tahoe will be out of beta in like 4 weeks.
Do you really think there are going to be significant UI design changes in that time? Beta 8 came out today and Beta 9 will probably be or be close to the RC.
By all means there are plenty of things to judge in macOS and there have been for a very long time. These for icons today are not it. The canary has left a very long time ago.