Most people are still using Java 8 (including android)...

Surveys don't seem to back this up any more... Yes there's a lot of Java 8 code. But more and more of it is maintenance rather than new development. Respondents of surveys that are able to list the versions they use in production (vs 'pick one') have indicated that for many teams with exposure to Java 8, they also have newer versions in production - showing that Java 8 is increasingly about maintenance than ongoing development (with the blocks to moving forward being a mix economic and technical factors).

The most dominant frameworks in the industry are ending their support for Java 8 - so not too far down the track, staying on Java 8 will mean that while you can pay for platform support, framework support is going to disappear anyway.

...we are currently at ~java 20.

Yes Java 20 is the current release, with Oracle's LTS being Java 17 (the previous ones being 17, 11 and 8 - with 8 having the largest paid support window).

Java 21 is out in a couple of weeks and will become the new Oracle LTS (other vendors and frameworks tend to align on this LTS designation so it continues to be important).