Maybe instead of declining take home assessments, then, you ask for an accommodation for an alternate assessment citing your anxiety as a disorder. If nothing else, it'll have them think.
Though, regarding your data. You've gotten 12 jobs that you got without an assessment. Which... well, that sounds like a lot of jobs. Yet you say you're eating peanut butter. So... were those 12 jobs... kind of shit? Plus, getting passed over 20 times is... not that much in tech, unfortunately. So... I kinda think you should ignore that data?
Tricky to elect younger & more competent when the older generation is so much more practiced at the schmoozing aspect, unfortunately. Not to mention better funded by special interests who trust their predictability.