What's the best way to create good presentations. Without spending too much time on the aesthetics.

I'm not going to suggest a tool, but rather a principle: keep it simple. This is especially applicable if you're unsure of what route to take. Here's a relevant quote: "A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away." - Antoine de Saint Exupery

I would want to see more visuals/icons or emojis that would communicate the idea than presentations that are filled with a lot of texts.

Canva is a great tool to make presentations. It has templates, styles, elements, photos, etc.

Try https://premast.com/ it has variety of options and help you create professional presentations