Vendor lock-in is always omni-present, even if you are using Kubernetes. The only difference is that the vendor lock-in you get when you run Kubernetes is mainly with the infrastructure layer hosting the code, instead of the code entrypoints.
Not to mention any managed services you want to use, which also will lock you in. So I don't do anything extreme to avoid vendor lock-in, other than making my code general enough to only have a small surface area for the lambda entry point. As a practical example, all of my APIs hosted on Lambdas are ordinary ASP.Net apps that would work identically if hosted in Docker containers.
Pricing so far is one of the biggest benefits of doing serverless approaches. I'm down to paying a couple of dollars per month for something that I'd pay tenfold for if doing Kubernetes. Both the monetary sum of only paying for what you're using, and also not having to worry about cluster maintenance, scaling and management is a godsend.
Not to mention any managed services you want to use, which also will lock you in. So I don't do anything extreme to avoid vendor lock-in, other than making my code general enough to only have a small surface area for the lambda entry point. As a practical example, all of my APIs hosted on Lambdas are ordinary ASP.Net apps that would work identically if hosted in Docker containers.
Pricing so far is one of the biggest benefits of doing serverless approaches. I'm down to paying a couple of dollars per month for something that I'd pay tenfold for if doing Kubernetes. Both the monetary sum of only paying for what you're using, and also not having to worry about cluster maintenance, scaling and management is a godsend.