for occasional onramp / offramp to USD i would suggest rockwallet
the fees (dealer spread + card fees) end up costing you about a 6% premium from what you'll see on spot but its the fastest and cleanest with the fewest # of hops

if you're looking to buy/sell in a rapid fashion then you don't need anything more than perps. you can get that on a centralised exchange like okex. binance recently relisted as well.