Email notifications for pages with dynamic tasklists display the tasklist in an almost completely unstyled way that takes up lots of space and are hard to read.

Email notifications that contain dynamic tasklists do not include a request for the tasklist.css stylesheet.
On a web page the DTL requires

<script src="/s/1403/20/3.0.4/_/download/resources/confluence.extra.dynamictasklist2:web-resources/tasklist.js" type="text/javascript">

in the head.
Emails containing tasklists do not request this resource. I would guess this is Confluence's fault and not the tasklist's.