Coinbase is corrupt AF. I used their exchange "Gdax" around 2016/2017 when BTC was booming from $2K. Gdax held a pretty hefty amount of BTC I was transferring in for around ~4 days, which is absurd since I went through thousands of confirmations (well above the norm for BTC at any time). The exchange would not authorize the transfer until I went on reddit to complain to a coinbase engineer. "Luckily" someone answered my PM after I saw BTC fall from 20K to 12K. This happened to me and quite a few others out there... makes you wonder why they had a really horrendous systems glitch right around BTC peak price. I had fun while the prices were low but I couldn't handle the uncertainly or instability of this stuff.
Coinbase is corrupt AF, but it is the least corrupt exchange because it is publicly traded. None can withstand financial scrutiny. All commit securities fraud, with their only defense being "crypto isn't regulated" so there is no such thing as fraud. They will all learn otherwise eventually.
Here are things all exchanges do:
1. Actively trade against their own customers. Since they have all client orders, they front-run all customers. It's like paying poker in Vegas with the casino at the table, and they deal the cards. This was basically what Alameda was with FTX. FTX "owned" Alameda, who traded against FTX customers. Oh, by the way, the knew all the FTX data AND could straight up steal FTX client funds. And this was the most "compliant" exchange. Binance, the world's largest exchange... doesn't even have an office or location made available, so they can't be raided. That's who you are trusting in this "industry".
2. Allow illegal practices like wash trading, painting tape, etc.
3. Don't enforce KYC and allow money laundering
4. Deal in and allow trading with known fraudulent "tokens", particularly stablecoins that actually allow the whole ecosystem to function. These are effectively dollar substitutes that are mostly fictitious and hot air. For example, Tether printed $3B dollars in the last week... look at what's happened to BTC price. Tether prints USDT, uses it to buy BTC, helps inflate the price. Those tethers trade for $1.... but are they backed by real money? No. BTW, all you need to do is redeem tethers.... but if you read their TOS they actually don't have to redeem anything.
I could go on, but I am tired of it... I have warned you guys time and time again. This is smoke and mirrors.