Your statement did leave some wiggle room to quibble over what exactly “very popular” means, though I don’t see how popularity is a useful metric when we’re talking about free software which doesn’t rely on user purchases for revenue. Ultimately it comes down to how funding the development of each software is accomplished, and whether that can be done effectively without selling out.

However, if we must compare funding strategies based on popularity, then we can. I’m not sure where you got your usage numbers from, but I’ll use your percentage to normalize for the number of employees paid through the funding strategies of both examples to compare the effectiveness of the approaches:

• Mozilla Corporation and Mozilla Foundation together have roughly 840 employees as of 2020 (the latest numbers available on Wikipedia). I’m not sure how they split up who does what for developing the software, but I seriously doubt the vast majority of those 840 employees are developers.
• Blender Foundation has a team of 31 people (as of 2022). Most of them are developers/engineers/designers directly involved with improving the software.

For purposes of discussion, I’ll assume that you are correct that Blender has 2% of the popularity of Firefox. Normalizing that for comparison, 2% of 840 Mozilla employees is 16.8 employees (round down because you can’t have 0.8 of a person).

In other words, if Firefox were only 2% as popular as it is now (thus making it equally as popular as you say Blender is), Mozilla would be paying 16 developers with it’s funding strategy.

Conversely, Blender is able to pay 31 developers using their funding strategy. This means that, even when accounting for popularity, Blender’s funding strategy is 2x more effective than Mozilla’s at paying developers to work on their software.

Again, I don’t agree that popularity is an important metric to compare here, but even when we do so, it’s clear that it is entirely possible to fund software without resorting to tired old capitalistic funding models that result in the increasingly objectionable violations of user privacy that Mozilla engages in lately. They could choose to do things differently, and we ought not to excuse them for their failure of imagination about how to fund their business more ethically. Especially when perfectly workable alternative funding models are right there in public view for anyone to emulate.