Stock market overvaluation and general economy shitfuckery doesn’t make it a pyramid scheme, which is a very specific type of financial crime.

Pyramid schemes involve organizations that can only survive with a constant flow of new investors because they don’t actually make any money from whatever the business is supposed to be doing i.e. selling goods and services to consumers.

Microsoft brings in significant revenue from selling it’s products to end users, which means it’s not a pyramid scheme.