Same vector graphics but different SVG output in CorelDRAW and Adobe Illustrator

Actually, a simple SVG like that could be stripped back even further. So, the Adobe Illustrator SVG isn't as "clean" as it could be.

For example, this one was made in Inkscape 1.0, saving as Optimised SVG, first removing all transforms and unnecessary attributes in the built in XML editor, and then optimising when saving by removing tags such as metadata and xml space, and unnecessary groups.

<?xml version="1.0" encoding="UTF-8"?>
<svg width="98mm" height="58.7mm" version="1.1" viewBox="0 0 98 58.7" xmlns="http://www.w3.org/2000/svg">
<ellipse cx="49" cy="29.3" rx="48.7" ry="29" fill="#4d4d4d" stroke="#2ca02c" stroke-width=".6"/>
</svg>

To answer your question more directly, there is nothing to stop you from manually editing the SVG. Also, different software has different approaches and tweaks you can apply to SVG output. Check the CorelDraw documentation to see what options are possible. Personally, I think it's probably a bit much to expect different applications to output exactly the same SVG.

Just as a side note, since Inksape is free, there's no reason you couldn't also use it to optimize your SVGs if you prefer to use a GUI instead of manually editing the SVG in a text editor.