Innovation usually takes a much longer timeline than just launching something and killing it with a year or two when it’s not sufficiently Google scale.

The world would have a lot less great products if this is how it was always done.

This is why startups continue to be the primary innovation source. They are willing to go through the hard grind to find product/market fit over multiple years.

Most of the products purchased by the big guys are at least 5-7yrs old (WhatsApp, YouTube, Waze, Looker, etc). There are some rare exceptions like Instagram and Android which were both 2yrs old at acquisition.