100%. It's also arguably the most irreplaceable. Just go through the thought exercise of imagining if a big tech company just vanished overnight. We'd all remember what they did and how the services work so companies could try to recreate the value proposition. This is how I imagine it playing out among the "Big 4."

Apple: If Apple vanished tomorrow I could get an Android phone that lacked some of the polish of iOS, but my day-to-day would be largely unchanged. Their laptops are still the best IMO, but could deal with a Lenovo if needed.

Google: Bing is fine. There are no shortage of online collaboration tools. Their dominance in AI is impressive, but it's not hard to imagine Microsoft reasserting themselves in Google's absence. Self-driving cars and life extension startups are well-capitalized. Their services are amazing, but not unique.

Facebook: Social media will find a way. If FB vaporized, something would fill the gap. Twitter would be given a new lease on life.

Amazon: It's almost impossible to imagine any company filling the gap they would leave. Who has the tech chops, willingness to deal with the grimy logistics and poor margins of retail, build out the cap ex of distribution, and deal with the politics of it all. Amazon is the most untouchable, irreplaceable company in tech. If I had to bet on one of these four companies existing 100 years from now it would be Amazon without question.