I always disable it. Having everything using the same exact colour palette is boring/homogenized. The themed icons are even worse, simultaneously killing iconography art and making it much more difficult to differentiate between apps in the app drawer quickly.
Over time I hate themed icons more and more. In like 2013 when I still used Android as my main phone I used to use them. But shortly after that I realized any customization I do myself is just… hideous? And ever since then I’ve hated all of it.
iOS recently added tinted and “dark” icons and they’re all horrendous.