I can put this in an email if you want, but one good reason would be that my laptop is probably faster than the cloud compute that they are willing to give away

I can put this in an email if you want, but one good reason would be that my laptop is probably faster than the cloud compute that they are willing to give away to 365 subscribers. I can do much more inefficient things in a single cell if I know my laptop can pick up the slack :) (Although, I'm guessing the reason they did it this way is so they could keep the execution model the same for Excel on the web? It's always running on the external service vs sometimes running locally and sometimes running externally.)