It's possible to extend H-1B status beyond the 6-year max-out period if the beneficiary is in the green card process. But if the beneficiary isn't in the green card process, then the most common option is the O-1 and while it's getting harder to get an O-1, it's still within reach of many talented professionals and founders.
https://www.courtlistener.com/docket/72095497/chamber-of-com...
https://www.courtlistener.com/docket/71541425/global-nurse-f...