It’s frustrating, I know. But, these functions were developed and added recently in Excel. IIRC, 2019 was already out by then. Newer functions are not backward compatible. Besides, the numbered versions of Microsoft Office are supposed to be a snapshot of a subset of the then Microsoft 365 featureset.

It’s not a defense by any means. Microsoft 365 is a well monetized product and probably a cash cow for them. Their money making practices are not all sound or even ethical all the time.

But for your own quality of use, if you’re going to share with other people, it’s always good to check out the support page of any newer functions to see which versions they’re available in. Here’s the one for SORT for example: https://support.microsoft.com/en-us/office/sort-function-22f63bd0-ccc8-492f-953d-c20e8e44b86c. It’s made clear that the function is not available in versions older than Excel 2021.

I still have access to LAMBDA in my install of office 2021. I may not have updated. Now I just won’t.

I’ve used password managers for as long as I’ve used the internet. I find it absolutely essential.

If you’re not currently using one, it’s likely that as the number of your login credentials increase, bad habits will increase. So it’s probably better to use a password manager any way.

If you’re using good, separate password, saving logins in the browser might work for you too. In that case I’d suggest you read up on the security your browser provides, ability to sync, migrate etc.