They could stand up their own version of Let's Encrypt with less than 20 people and $5M/year. It is inevitable. Let's Encrypt had a budget of $3.6M and 13 employees as of 2019 [1], but I don't have recent funding and staff figures as of this comment (replies with context welcome!). Probably spread the cost across the BRICS to make it US sanction resistant.
[1] https://news.ycombinator.com/item?id=24085559 (citations)