With post covid interest rates this strategy very rarely makes sense. Even people like zuck getting fully collateralized loans against their stock will still have to pay close to 5%. There are certainly circumstances where it makes sense to take a 5% loan, but they are few. It does not make sense to just roll loans over forever anymore. Thats why all the big tech stocks pay dividends now. Founders dont want to sell and they dont want to take loans.

Buy borrow die also leads to massive estate taxes which is why billionaires use trusts instead. Buy borrow die is best for people with around $50 mil in assets because they dont have any estate tax.