When listing benefits, any competent person would always list both pros and cons. That's to avoid being bias. So can you list the cons please? That would include what happens after segwit gets activated... LN for example?
You can read all about that in the source. The Bitcoin Core team was pretty objective when assessing the downsides of Segwit. This is why I've added the source.
Malleability Fixes - not fixed. just offering a 'opt-in' keypair type thats disarmed from doing malleability (only the innocent will happily disarm)
It is fixed. Nobody has claimed that it was fixed for the legacy keypairs.
Linear scaling of sighash operations - not fixed. just offering a 'opt-in' keypair type thats disarmed from doing quadratics (only the innocent will happily disarm)
Same as above.
same for the rest.
This is a lie. You don't understand Segwit.
-snip-
Forcing users into Segwit keypairs is not something that I'd exactly support, although I wouldn't strongly oppose it as much as I oppose certain things. Prioritizing native -> SW and SW -> SW is fine with me and tackles the native key spam problem very easily.