The fediverse already has a mechanism to guard against some corporation coming in and taking the code from a platform and building a commercial product on top of it - defederation. We don’t need GPL to “protect” us from anyone here

I disagree. The reason GPL works is that legal action (Such as from GNU foundation or EFF) deters bad actors.

The fediverse already has a mechanism to guard against some corporation coming in and taking the code from a platform and building a commercial product on top of it - defederation.

Defederation only helps the corporations: When the corporation comes in, overwhelms the fediverse with their huge network of active instances and then defederate, the only ones holding the bag are the open intances. . It's much easier for a private corporation to get numbers to defederate and come out on top than for open source enthusiasts.

However, there are also many that want to be recognized (financially) for their work. GPL ignores the latter.

If you want to be financially recognized for building on top of other people's open source projects then you should write proprietary code. You shouldn't be allowed to take open source works freely and call the entirety your own. MIT doesn't prevent that from happening. GPL prevents that from happening.

I don’t believe that is the case any more

It's actually really important in the long run. There can never be true open source without GPL or similar legal licenses.

I would argue that by sharing code it makes everyone more productive because you can borrow code from other places and improve on it rather than having to reinvent the wheel because the plugin you want to improve is proprietary. Anyway that aside my problem with this is on the desktop permissive licenses are fine because the user using the software can choose not to install any proprietary addon's. In the case of the web this is now controlled by the person hosting the service. AGPL ensures that the ecosystem remains open. With a permissive license on the web the only way to ensure an open environment is to host your own instance yourself because you can't control what any other instance does. Personally if I were a Lemmy host I'd use sublinks but I'd always ensure any changes were openly shared since I feel as though that's the only way to be fair to your users...but as a Lemmy user I wouldn't touch it with a 10 foot pole unless it was my own instance since there are plenty of AGPL Lemmy instances to chose from. Lastly GPL does not require you to release your code publicly. The only requirement is that your users have access to it. That means it is fully in license to sell software, the only requirement is that the people who bought your software receive code and are able to redistribute that code. Yes, that is a tad purpose defeating but the official upstream never has to be made public and ultimately people redistribute all kinds of software whether open or closed source, whether allowed by the license or not. As far as I'm concerned if the official version requires purchase most users are likely to pick that over other options. RHEL is a good example of this. AGPL obviously makes everyone visiting the site a user so it's less able to facilitate that but I figured I'd clear up that misconception.