It is always good to have more reliable mixing services in crypto space, but I think Chipmixer is the king for now.
You will have to work hard to compete with them, as minimum deposit is 0.005 BTC compared to Chipmixer 0.001 BTC. That is five times more!
Free mixing option is interesting idea but service fee is a bit high for full version (4.9%+0.0007 BTC)
Is there any advantages that I am missing here, compared to Chipmixer, Samourai and Wasabi wallets?
The free mix is to trial service and is only for deposit amount of 0.001 BTC
You have identified one main advantage, it is always good to have more reliable mixing services in crypto space, but you can see on the posts above yours that they admit participants and moderate incoming Bitcoin supply.
0.005 BTC is not very much, likely the amount will reduce as the value of Bitcoin increases.
-DA.