What’s a company that objectively improved after it got “bought out?”
I don't think that's a fair comparison. Youtube only existed for less than 2 years as an independent start up. There's no way to know what it could become as an independent tech company.
Should I buy a Pixel or a Samsung?
If you are able to get the the Pixel with a deal, go for it. Pixels don't retain much resale value, like Samsungs. For example, the Pixel 6a launched at 450, now it's in the Google Store at 250.