Smart, wealthy shareholders love cash hoarding. Especially if the cash is held tax free in overseas accounts.
The share price is boosted allowing them to get returns in the form of pure capital gains.
If the company were to pay dividends, sure, most of those dividends would be taxed at capital gains rates as well. But that money has to be taxed at the highest US corporate income tax rate first. Thus, significantly reducing overall value.
To go a step further, the wealthy don't even have to cash out their shares as the price climbs and climbs. They can get low interest loans using the shares as collateral. This deferring taxes indefinitely and leaving all their capital in these huge companies that are outperforming the SP500 anyway.