This is called Secure Boot, it's part of the UEFI standard which replaces BIOS. Nowadays it's supported OOTB by most major distros (Fedora, Ubuntu, Debian, ...), but you can usually disable it with a simple toggle in the UEFI config menu.

Wait until people make the tools required to unprotect the BIOS on the brands doing this, if they are. Not much else to do at that point than either wait or just buy from companies making laptops made specifically for. That, or if you are in the EU, complain like Hell that a protected BIOS on a laptop is anti-consumer if it doesn't let you boot anything besides what the vendor allows and hope they look into it a decade down the line.