As far as I know, .et is the TLD of Ethiopia, and .eth may be confused with .et, so ENS DAO could not apply .eth as a TLD.
How about submitting .ens TLD application to ICANN?
If ENS DAO owns .ens TLD, ENS user can set traditional DNS information on-chain, such as IP . On-chain traditional DNS information could be synchronized to traditional DNS service by an off-chain service.
For example: The admin of www.abc.eth can set the A Name of www.abc.eth to 202.121.1.12. The website https://www.abc.ens can be opened on any browser.
Reference: