Flash game sites were still huge and popular after Adobe’s purchase, so clearly it did not kill it. If you mean something like that the acquisition started the death… that’s a hard position to argue against, since it’s subjective. Perhaps you’re right.
When flash started to fade for games, many developers moved over to adtech where their skills were still valued. Flash continued for a few years to power ads as well as shims around other videos that would collect data and even trigger secondary ad auctions.
Adobe had competing products mostly based on open standards. They shut down many active product lines and merged what was left into Adobe AIR, which didn't take off.
