I suspect it's the same reason game devs are hot for streaming. When the code only runs on machines you control, piracy becomes impossible. By contrast, trusting people to respect licenses on code on their computers is how piracy happens.
In my opinion this is a feature, not a bug, but the business reason is clear for why all commercial software is moving towards the SaaS model.
How much game piracy happens these days? Since steam became such a good distribution platform and my internet connection got fast I haven’t even thought about pirating a game. AAA titles are expensive, but there aren’t a ton of them released every year, and downloading cracked installers is a huge security risk.
In my opinion this is a feature, not a bug, but the business reason is clear for why all commercial software is moving towards the SaaS model.