Maybe medical? Like, Bio-Ntech designed the COVID vaccine, Pfizer bought it and could wrap up the phase 3 trials and then scale production?

So, they didn't actually make the product better, but they probably made it viable sooner than if they hadn't bought it?

But that is kind of the normal process for the medical industry at this point..start ups developing new medicine and then shopping it to Big Pharma for buyouts or funding

Oculus. No way they would have otherwise had the money to make cheap standalone VR headsets like the Quest.

Jaguars supposedly got much more reliable after being bought by Ford

I don't think we should be too surprised by this. If a company isn't all that good before a conglomerate buys it, then it's unlikely to be widely known. Conversely, if a small company is widely known, it's likely to be exceptionally good. So, even if acquisition usually just results in regression to the mean, we'll still mostly have heard of ones that degraded the company.

Bethesda buying Id Software.