Volunteers can’t be blockers
Quoting: Volunteers can't be blockers - Duck Alignment Academy —
As your project grows, you add processes. This, of course, requires humans to make the processes go. In open source projects, contributors often come and go without warning. This makes it difficult to depend on a particular individual for a critical task. You never know when they might silently disappear. This is not a knock against volunteers. They are the lifeblood of open source communities and they have every right to step back when they need (or just want) to.
If your project has people who are paid to work in the community, then they should be the load-bearing contributors. Paid contributors will still have periods of unavailability and may leave with short — or no — notice, but you can generally expect them to be around more often and more predictably. Again, this is not a value judgment, it’s a matter of capacity planning.