but the Pulumi backend documentation explains that only Pulumi Service supports transactional checkpointing (for fault tolerance and recovery), concurrent state locking (to prevent corrupting your infrastructure state in a team environment), and encrypted state in transit and at rest. In my opinion, without these features, it’s not practical to use Pulumi in any sort of production environment (i.e., with more than one developer), so if you’re going to use Pulumi, you more or less have to pay for Pulumi Service.

https://blog.gruntwork.io/why-we-use-terraform-and-not-chef-puppet-ansible-saltstack-or-cloudformation-7989dad2865c Is this all still accurate?

nope. 🙂

that's what I thought tbh. We've been using Pulumi for more than 3 years, and for multiple customers.