Why would those blocks be orphaned?
What is required for scaleability then according to you?
There is latency in block propagation
in a truly decentralized network on the public internet. The latency will grow larger with bigger blocks. Blocks are in competition to be added to the blockchain based on the cumulative difficulty. A staking node can produce a block with a higher difficulty before a block from another node is propagated towards it and will orphan the competing block. This is less of a problem when blocks are smaller. In the private 10 Gb/s intranet the latency between the staking nodes is negligible, transaction throughout can be very high.
What you do with the blockchain size is not related to the above, is another big scalability problem.
The dev team has done a lot of research on the latency and is well aware of them when they designed the solution in the beginning. We have overcome "cumulative difficulty" in our solution. Do note that we have taken a lot of things into consideration when working on this. Your problems stated are block chain problems of yore. We had the benefit of understanding those problems when we started off with block chain 2.0.
Sometimes, it is good to look at things from outside the confines and constraints of the current problem and one will see it in a different light.
Do note that you are speaking in context to
"in a truly decentralized network on the public internet.". This whole topic is about a private block chain. So, we need to be on the same page.