To get any real improvement over optical you would need both a TV and a receiver that has eARC. Both ARC and optical are limited to a maximum of 5.1 SD audio. Optical can also be far more reliable than ARC, I've long given up on ARC having a hissy fit every so often. The only real advantage of ARC has over optical is if you have an Atmos speaker layout and subscription to Sky or streaming services that have Dolby Atmos via Dolby Digital Plus.
It would actually be harder to find a receiver under six or seven years old that doesn't have ARC or the ability to decode Atmos.
As above ARC relies on CEC which can be very frustrating with many kit combinations so whilst ARC is great in theory many folk find Optical Digital audio between the TV and their sound system far more reliable.