Segwit's goal wasn't the blocksize increase, so it's wrong to criticize it for it. And being opt-in is the result of softfork, and softforks are great because they are much less disruptive than hardforks, so there's almost no risk of chain splits.
It's also wrong to say that SegWit was complex, all you had to do is update your wallet software and create a new SegWit-compatible wallet. Some services did this only after a few days or a week after the fork, big services like Coinbase just didn't care about their customers, which resulted in huge fees later in 2017.
no risk of chain splits......................
........ apart from the one caused in august 2017 to actually get segwit activated
for years peopl have been begging for devs to scale bitcoin. devs came up with a scaling roadmap. segwit was the stepping stone for that.. so critisizing segwit for not helping scale bitcoin is warranted.
segwits goal was to make using normal bitcoin transaction formats 4x more expensive.
segwits goal was to make bitcoin more compatible with a separate network thats not a blockchain and not a feature for bitcoin. segwits goal was to open a backdoor so devs can now push things into bitcoin without consensus
so step one of actually scaling bitcoin. get rid of the hideous witness scale factor, which will achieve:
1. transaction bytes being again counted correctly and fully
2. transactions not being pushed up in price
3. the 4mb 'weight' actually being fully utilisable
4. we may actually see transaction counts finally surpass the 600k a day limit thats been around for nearly 10 years now