AWS has a service called S3 Object Lock that provides a WORM model:
https://aws.amazon.com/blogs/storage/protecting-data-with-am...
https://aws.amazon.com/blogs/storage/protecting-data-with-am...
Sending every change to everything up to AWS would be wildly expensive both in bandwidth and cash. It would also put all of your data "in the cloud" (aka on other people's computers).
Plus a ransomware attack on AWS would make the backup unavailable.
A small, local device that contains a memory cache could write a DVD once half the cache is filled (double buffering).
A double-sided, double-layer DVD can hold 16GB so an "inline cache" with 32GB could copy and store a DVD worth of disk backup and then write a DVD.
BLU-RAY can store up to 50GB
For business use, I think any backup/archive system that keeps multiple backups should be safe enough against ransomware since you can restore from the newest uncorrupted backup.
Tape is wildly expensive for some reason. This seems odd to me. I wrote a tape-based archive system in the 1970s. Most technologies have gotten cheaper. Tape has not.
I'm not aware of any Blu-ray robots so at large scale your choices are limited to disk, tape, or ODA which are all fairly expensive.
Dvd's are unreliable as a long term storage media due to physical damage or if it is a rw dye decay