I am Jùnliàng, a Babel contributor since 2019. I would like to share my perspective here.
GH is a platform where people collaborate on developing softwares, so the contribution graph is engineering-biased. But operating an OSS, especially like Babel which is serving millions, is just like running a company. In a company we have different roles, none of roles is more important than the others. In Babel team, Henry spends most time on reaching out to contacts in companies, giving talks, syncing with different projects in the ecosystem, offering mentorship to junior contributors like me. None of these is visible on GH but they are vital to sustain the project, to attract both new company sponsors and contributors.
2020 is a hard time for any reasons. Before we talk about funding with team, Henry has already voluntarily pooled less money ($11k to $8k) and another long-time core contributor Brian (https://github.com/existentialism) stopped taking money. While this helped bumped up our balance, everyone taking less is a dangerous signal to an OSS: maintainers constantly fighting with financial insecurity may burn out or stop maintaining in order to recover from the mental pressure about "I am responsible for this".
I maintained small side projects like (https://github.com/JLHwung/postcss-font-family-system-ui), where the feature set is frozen and most maintenance works can be automated by bots. This is quite unlike Babel: The feature is open-ended because the language is evolving. Various edge cases should be take cared. Tradeoffs between spec compliance and output code size should be made. It is not a side project that I can dedicate part time efforts like 10hrs/week to work on.
Speaking for myself, I spend around 40hrs/week to meet my own productivity requirements. I don't think I deserve more than other paid team members because everyone has different time constraints and we don't track work time meticulously.
To avoid burn-out and not let Babel consume all my energy, I spare some time on encoding Chinese characters in Unicode, which, just like Babel, has profound impacts on ecosystem but long overlooked and underfunded. I helped submitted hundreds on characters in IRGN2487 (https://appsrv.cse.cuhk.edu.hk/~irg/irg/irg56/IRGN2487UKData...).