It's true that worker mode is not supported in Android apps, but you can do a quick test to work out if it's relevant: disable worker mode and try it in the Chrome browser. If it's still better, worker mode is most likely not relevant. If it causes the same performance issue in the Chrome browser, that's actually quite good news since it suggests supporting worker mode in Android apps could improve the situation.
I think filing issues as I described is still the right way to approach this: the more issues filed by the more users, the clearer it is to Google that it's a significant problem that ought to be prioritised. It also increases the chance one of these reports hits on a discovery that helps get to the bottom of the problem.
People have long tried to suggest "make a native engine" as a solution to every HTML5 problem, but apart from the fact it is probably infeasible anyway, it may well not actually solve the problem - lots of other tools with native engines have users who make similar complaints about poor performance on Android, like here, here and here. Android graphics drivers are notoriously poor. If that's the cause of most of these types of problems, writing native code does not save you from that.
Trusted Web Activities (TWAs) are interesting, and you can probably try them today with an existing HTML5 export. The big problem though is they are not Cordova, so you lose IAP, ads, and all other third-party addons that involve a Cordova plugin. There's a Digital Goods API that may allow for IAP only, but you still need a full web export, hosting, and a lot of configuration with the Play Store. Do you think that's viable? We could try to support it better if that level of mobile support would do.