While its true that KYC is really not necessary for cryptocurrency, its still meant for monitoring laundering and illegal activities.
Exchanges are mandated by the government to collect these data from the users of the decentralized markets. They are going to make it like it's a crime to use services without sending them the documents and you won't be able to withdraw funds.
And most of the time, local crypto exchanges are asking for KYC so if you want to convert your crypto to your fiat, you have no other option but to submit your docs unless you will use p2p services. Anyway, make sure that you are sending your info to legit crypto-exchanges. But for other exchanges, you can still enjoy trading crypto without submitting your KYC if you withdraw below their max daily limit, usually 2 - 3 bitcoin. Which for me is already good amount especially for those small traders. We need to understand that legit crypto exchanges are requiring KYC as part of their license.
2-3 Bitcoin/day max withdrawal for a day is already sufficient enough for most traders but there are indeed users who do transact way more than with that amount which it isnt
really surprising that they would really ask out for further verification yet platform are regulated with government which does mean that theyre still included
into those terms which had been mandated for them to follow and as a user then you wont really have any options or choice but to comply on whats being asked.
Lastly, this is just some obvious swapzone.io advertisement.