Hello 
,
yes, this is correct.
Many mail providers provide cloud storage in addition to the email account.
Therefore, in my opinion, the best solution for large files is simply to send a cloud link.
Then the recipient can decide whether and when to download the file.
In addition, not so much memory is occupied in his mailbox.
A possible link password can be transmitted in encrypted form via DC.
Unfortunately, iCloud links only work with other Apple users.
But there really are enough other cloud providers.
By the way, it is also possible to mimic the status feature of WhatsApp in DC with a cloud service.