Unless you enjoy holding paper monero, and letting centralized exchanges get away with fractional reserves, always withdraw your crypto!
Even better idea, don’t buy Monero on a centralized exchange and don’t sell Monero on a centralized exchange. Use decentralized exchanges only.
CEXs are important for the xmr ecosystem. The least fees, quick and convenient. They should be avoided if possible, but in reality, it’s not very possible.
I mean, it is very possible to avoid CEXs. I just choose to take advantage of them while they (Kraken) haven’t banned Monero from their exchange (RIP belgium and ireland)
Looking at the long term though to provide an indestructible on/off ramp we need DEXs, I’ve tried out Haveno Reto and it’s looking good: https://github.com/retoaccess1/haveno-reto/releases/tag/v1.0.7
jokes on you, you can’t buy monero on centralised exchanges!
Kraken! (At least in the US)