Companies buy back shares as a different way than dividends to enrich their shareholders.

Exactly: enrich shareholders at the expense of their own coffers.

> enrich shareholders at the expense of their own coffers.

This makes no sense. The coffers belong to the shareholders.

“belong” is a flexible word. You’re right in theory but depending on the situation money in your bank account is worth more to you than an equivalent amount of money in a company’s bank account (of which you are a shareholder).

In big tech’s case it’s mostly to offset massive stock compensation of executives and insiders