I think decentralized exchanges are appropriate for your needs. There are many exchanges like that, now there are binance dex with very low cost that can meet your needs. The limitation is that it only supports beep2 platform and the volume is quite small
The volume is not sufficient to meet the requirements on decentralized exchanges and the lack of smoothness makes it hard to trade on these trading platforms. Afaik, the DDEX exchange has very low trading fees for both maker and takers. Makers should pay around 0.1% and the takers are supposed to pay approximately 0.3$. IDEX also has a similar fee structure: For makers: 0.1% and for takers 0.2% IIRC.