evidence... hmmm
how about people frustrated with bitcoin to such a point they are actively promoting LN....
how they are frustrated with waiting for bitcoin innovation that they are willing to losen their morals and principles and understanding of bitcoin to actively want to have a different network where funds are locked into counterparty management(banking).

every person that WANTS LN are people secretly pee'd off with bitcoin fee's and limited transaction ability... if they were not peed off, and happy with bitcoin. they would not be so hard nose about promoting LN as LN would not be something they would want/need
in essense. if there wasnt a problem then LN would not be a solution.. so those promoting LN are actually announcing and screaming there is a bitcoin problem.

but the 'problem' is not technology.. but political decision of devs' to not innovate bitcoin and instead stifle bitcoin to make LN a thing people desire

as for segwits stuff that core pretend are fixed
maleability.. has not been fixed. people can still malleate on the bitcoin network by using legacy
infact new opcodes for segwit allow segwit to be malleated too... yep core want/are reintroducing malleation into segwit.. (i know i laughed hard when that became public knowledge)
as for the legacy transaction s in regards to the "quadratic" verification.. that can be solved real easy... dont let a single transaction be allowed to have 16,000 sigops. this then solves 2 things
a. if a transaction is only allowed say 500sigops. then their wont be any issue with sighash validating.
b. blocks wont be filled by just 5tx's of such bloated crap.

funnily enough.. core when keeping the baseblock but then shifting to weight. didnt DECREASE sigop limit to eleviate the problem.. instead they increased the sigop limit
it was 20k blocksigop limit with a /5 for tx sigop limit... to then be a 80000k blocksigop limit with a /5 for tx sigoplimit
(4k to 16k sigops per tx).. which was an unbelievable foolish move.

at worse they could have done 80000 /20 to atleast stick to the old 4ktx limit.. or improved the situation by doing a 80k /100 to get transactions to only be allowed 800 (though i personally think 800 is still too much for a 'peer-to-peer' decentralsied currency)