Accessibility Optimization

I would like to see accessibility optimizations. I just watched a webinar with Equalize Digital - where they tested several form providers - and in the webinar, they mentioned using helper text for example - under the label and not in a tooltip (because the clickable area of the tooltip icon is not big enough to be accessible) - and to use aria described by instead of labeled by on the helper text because aria labeled by will override the label etc... Also fieldset is for groupings like radio buttons and checkmarks and not for the entire form if I understood correctly - so a screen reader will read out the form entirely. Those are just two things I can see could be improved by taking a quick look.