It’s not weak. Originalism is weak. It basically asserts that the constitution and all amendments must have been written by psychics who could predict every situation that would arise in the future, forever.
Of course things written decades or centuries ago couldn’t predict what’s relevant today or five decades from now, so of course they should be open to interpretation as the needs of society change. It’s the difference between following the spirit or the letter of the law, and it’s why most laws aren’t merely prescriptive, but outline motivations and goals.