Don't know if it has been mentioned yet, but I am using an app for Android called Precise Volume, it has a system wide parametric equalizer + ability to override volume steps, so for example, I have a Poco F3 that only has like 15 volume steps by default, so every step is too steep, I can't get the right amount of volume I want, as it's either too little or too much. With this software, you can have like 50 steps for example, similar to my Windows laptop.
It equalizes any common app I tried, such as Youtube or some music apps for example. Also, it has an ability to import an eq txt file compatible with APO format, so if you are using Equalizer APO in Windows, even with Peace, it's perfect, as I only have to copy paste the peace.txt file with the current EQ and it works.
So if you want a system wide equalizer for Android and also to increase the volume steps that suck in most Android phones (too little of them), it's perfect.
100+ Volume Steps, Parametric Equalizer, Boost/Reduce, Automation, AutoEQ & More
play.google.com