I have found that the exchange rates on decentralized exchanges are usually a bit worse than on centralized ones.
This is unfortunately true if you are a new user. As a new user, you will probably struggle to have someone accept an offer you make and will instead be limited to being a taker, unless you are offering the only trade in a certain currency/method/country/etc. However, if you build up even a small reputation on your account as being a trusted user, then you'll find people will accept your offers and you can set any rate you want. When I trade on DEXs, I often end up with a rate a couple of percentage points in my favor over centralized exchanges, and minus many of the fees.
If all you have is 0.1 BTC and you want to trade all of it on Bisq, you can't because a piece of that pie has to be deposited as a security deposit.
That's a feature unique to Bisq (or at least, unique from all the DEXs I have used). Neither LocalCryptos nor HodlHodl require this.