The word "indispensable" means something or someone that is absolutely necessary or essential, without which a task or situation cannot be successfully completed or existing. Full definition
The messaging app has become indispensable for many segments of society, especially for the crypto world. (bitcoinist.com)
It is an excellent tool for collaboration, and, though its charms can sometimes distract less motivated students, the Internet has become indispensable in the modern laboratory. (sciencemag.org)
They have become indispensable parts of our daily life, and we can't even begin to imagine just how empty our lives would be without them. (blackdogrescueproject.com)