Excel validation lists avoid blanks and errors with TOCOL(ignore) plus FILTER; the spill range stays stable across worksheets.

Use dynamic arrays and tables for fast, scalable cascading drop-down lists in modern Excel.

Excel used to be the poor schmuck’s database, with spreadsheets that just sort of sat there. You could create something more sophisticated with LOOKUP functions, but they were a huge hassle to set up.

The article How to use Microsoft Lists to organize Excel data you must track or share is an introduction to sharing Microsoft Excel data with other users via a list prepared by the Microsoft Lists app ...