Segwit allow cross blockchain atomic swaps, so trading without trusting your coins to exchange possible. SegWit allow off chain transactions, so private transactions without coinmixers possible. SegWit allow instant transactions and allow more transactions per second. No matter how good or bad today implementation is, SegWit is a step in the right way. Network should progress, anonymity matters, big tps and instant transactions is a must. Once litecoin adopts segwit all shitcoins become obsolete, so no wonder miners trying to derail voting and spread FUD here and there.
You are confusing Segwit with LN,
Segwit only allows the TIME LOCKING of BTC onchain.
LN does a counterfeit offchain transactions, because if those time locks fail, you are trading fake coins.
Which you only learn it is fake, if you try cashing out on the TRUE ONLINE CHAIN.
Well, SegWit allow Lightning Networks. Without SegWit LN probably will not happen. And what does it mean IF those time locks fail? Why should time locks fail, because of what? If you think there can be problem with it - please show it on test network.
If bitcoin splits on two hundred altcoins, if artificial intelligence robots attack us, if government builds quantum supercomputer to hack dogecoin there definitely will be some problems with cashing out too. That's very unlikely, though.