People who think this look at a product made by 83,000 people and to them, it looks pretty similar to a product made by 83 people.

Some of those workers are working on a large-scale product that scales imperfectly. Sysadmins to rack new servers, human moderators to respond to users' reports, whatever. 1 per 20,000 users and a few billion users is a lot of workers. On the other hand, none of these companies are famous for their high-touch, responsive customer support.

Some of those workers are working very intensely on things that are completely invisible to end users. Applying security patches to backend servers. Training their workers to recognise the signs of modern slavery. Building their own in-house Linux distribution. Products that get cancelled before launch. Getting that newly acquired company onto your corporate platform.

And some of those workers are working on things that are marginally invisible to end users. Ad sales, feed ranking algorithms, spam detection.

Some of those workers are working on new, customer-facing but peripheral things, that have escaped notice because they're at a small scale, or unpopular. Shorts on youtube, for example.

To a critic, these manual scaling support, invisible and almost-invisible efforts don't count - and if you only count customer-facing features, that seems like a lot of developers and not much development.