On bisq you can even buy with a negative premium. Also, I like how it works : It is really decentralized, on Tor and It gives me the feeling to really use bitcoin because you have to make some transactions. Negative point : it is only on desktop (for now)
Discussion
I have just installed bisq. I must admit that it looks more complete than robosats, with all the stats and tweaks it's looks like a decentralized exchange while robosats or peach looks more like a simple market of classified ads.
There's only bitcoin on-chain on bisq right ? No lightning ?
Did you tried to buy XMR or stable there too ?
On chain only. I never did stable or xmr. But is possible to use them in theory