Explosion's core contribution (not moneymakers) is the great SpaCy library they first released in 2015. It was an excellent work, far better designed (IMO) than NLTK and other offerings at the time. Of course the library isn't monetized. SpaCy too has the ability to train custom models and use them.
This never transformed into a model hub. Despite a lot of people using SpaCy and probably building custom models.
Again in contrast, Explosion's other revenue stream (prodigy) is not a SaaS as well. Its a great software, and I presume it brings in a steady income. But in 2023, I would imagine that HF's LLM hosting, cloud training environment, brings in more money than Explosion's data annotation software.