Why not copy the best in business?

Why OTT platforms don't copy YouTube more closely and launch a free tier which is ad infested low resolution? This way instead of constantly giving out trails people can get used to the app and eventually buy the subscription. The other benefit is the people who wouldn't ever pay or are in no financial capability to pay would consume ads and Netflix/Disney would generate an ad revenue like YT has. Win - Win, right? What do you think?