This plus because you can dockerize and run on lambda, essentially you can run most anything these days (most things i've encountered are reasonably easy to dockerize, i'm sure there are exceptions, but in the main easy)
There's a very interesting blog post about it here, as well an an accompanying whitepaper: https://brooker.co.za/blog/2023/05/23/snapshot-loading.html
3) Also you can pay for provisioned capacity[1] if the cold start thing makes it worth the money, though also just look into fargate[2] if that's the case.
[1]: https://docs.aws.amazon.com/lambda/latest/dg/configuration-c...