Experience Banks

Experience banks would be a new block that you can use to store your XP so you can avoid losing most of it upon death.

The block would be crafted using obsidian, a Sculk Catalyst, and potentially other items. Maybe it could act like an Ender Chest in that each player gets their own XP pool that can be accessed from any bank. This would require the crafting recipe to include an Eye of Ender or an Ender Chest. If this isn't the case, the block would drop the XP stored inside it as orbs when mined, similar to Sculk blocks.

As for how it's used, the experience bank would have a UI showing how much XP you have on hand and how much is stored in the bank (these would be shown as levels + experience points, e.g. 9 levels + 10 points). The UI would have two buttons on it, deposit and withdraw. Clicking these buttons takes you to another UI that allows you to select the amount of money to deposit or withdraw by setting the number of levels and the number of additional experience points not included in those levels. You can't deposit more XP than you have on hand, and you can't withdraw more XP than is in the bank.

The deposit UI could also include one or more item slots where you can put Bottles o' Enchanting to deposit XP from them while leaving behind the bottles, depositing a random amount of XP per bottle (same as the XP released when smashed normally). If the XP pools are per-bank, you could also use hoppers to feed Bottles o' Enchanting in, depositing the XP automatically.