Yeah, because people use python when it doesn't matter and c++ when it does (including implicitly by calling modules that are backed by c implementations).
That is not an option with FHE. You have to go all in.
And people will use FHE where it matters and plaintext where it doesn’t…
Yes but with FHE it also depends on the use-case and how valuable the output is and who is processing it and decrypting the final output.
There are plenty of viable schemes like proxy re-encryption, where you operate on a symmetric key and not on a large blob of encrypted data.
Or financial applications where you are operating on a small set of integers, the speed is not an issue and the output is valuable enough to make it worth it.
It only becomes a problem when operating FHE on a large encrypted dataset to extract encrypted information. The data extracted will need to offset the costs. As long as companies don't care about privacy, this use-case is non-existent so its not a problem that its slow.
For military operations on the other hand, it might be worth the wait to run a long running process