After you have the money in Ready To Assign, did you have an overspent credit card category in the budget? If I try to replicate what you did, I do indeed have the money in Ready to Assign but I also have an overspent credit card category, and the fix would be to assign the RTA money to that credit card because you sent more to the credit card than you had set aside for the payment. If that's the issue, see https://support.ynab.com/en_us/when-your-credit-card-payment-category-is-red-a-guide-SJDSr3Q1i

That said, I usually don't have to do this so perhaps the reason is that you had some credit card payments that weren't budgeted for (maybe you only started with YNAB recently?).

Yeah I mentioned this more or less in another comment but this is currently my preferred approach as well 👍

Yeah on the one hand, you want the fine-grained detail of separate categories for everything but then again, a general vacation category saves me a lot of headache.

I've seen people use the Wish Farm approach and first tag the transactions (e.g. #2023-sydney) using the memo field, and then delete the category which will prompt YNAB to reassign the transactions and remaining money to another category. So a specific trip could go to "travel", something for the house could go into "home improvement", a new drawing table could go into "hobbies", etc.