⭐ Merited by bitmover (1)
The only downside of segwit addresses is that they do not allow to sign messages. Only Electrum does, and its signature is not recognized by Bitcoin Core.
SegWit DOES support sign message, but there weren't any standard about sign message so Electrum decide to make their own standard.
The only standard that i know is https://github.com/bitcoin/bitcoin/pull/16440, but it's still on progress.
core devs are being too hard-assed about it in my opinion
we don't sign a message from an address. we sign a message using the private key just like we sign anything else including transactions with that private key. and the standard is already there (add a fixed string at the beginning -> double SHA256 hash -> sign -> encode with base64 with a recid).
that is what we have been doing all this time with legacy addresses and that is what Electrum continues to do with all types of addresses.