I am using Tor to access .onion mixer link, but I tried it with Orbot on a privacy browser like Duckduckgo, not on browser like Chrome, Edge or Safari.
I downloaded Orbot, I enabled Duckduckgo on my mobile phone, I went to Duckduckgo browser and .onion sites are not working which is normal because I disabled Orbot first. I started Orbot, I used the mixer .onion link and it was working and I was able to mix my coins.
Is this idea good as an alternative to Tor browser?
There seems to be some kind of confusion between the use case for Orbot and Tor browser _act_. They are both designed to give access to the Tor network with a small difference : Tor browser is a fork of Firefox that allows you to browse the internet behind the Tor network (and bridges) while Orbot ends up being a VPN for smartphones whose aim is to route traffic from any installed app that you have on your device through the Tor network. What are you trying to achieve in looking for an alternative for the Tor browser (that, as you could see, ends up using the same network)?
As an additional note, I don't know where you installed Orbot from, but usually the newest updated version can be found on their GitHub[1] page. Even if you don't usually install the Beta versions, the latest stable release that can be found on GitHub is
v17 RC 1 (tor 0.4.7.11) while the Google Play store version[2] still sits on the
v16.6.3-RC-1-tor.0.4.7.10.
[1]
https://github.com/guardianproject/orbot/releases[2]
https://play.google.com/store/apps/details?id=org.torproject.android