Because HTML was a document format, not an application container. Try positioning something exact in Latex.
<table border="0" cellpadding="0" cellspacing="0"><tr><td>...
<code>(SUB X Y) </code>subtract<br>http://okcancel.com/comic/98.html
... When people realized that you could, painfully, use CSS for layout and dump layout tables altogether.
Html shouldn't consider layouting, that's for css to do.
In addition, the attributes you show are now obsolete and non-conforming: https://html.spec.whatwg.org/dev/obsolete.html#non-conformin...
Besides, HTML does allow precise positioning, but nobody really needs it. What everybody needs is a high-level language that fits the domain: fluid 2D interactive layout. CSS is simply not a good attempt to solve it. It's not even bad per se, because a similar model works quite well with XSL-FO. But XSL-FO is always an intermediate step: you take a custom document format (some XML), transform it with XSLT into XSL-FO, and then process XSL-FO to produce a PDF. The HTML lacks this transform step and tries to bolt-on CSS model directly to what must be a custom XML format and this is why it's so awkward.
It was promising, but it was mired in over-engineered complexity, the w3c docs looked like a nightmarish "design by committee" mess. I believe the intention was never to actually have to see XML let alone write it by hand. Along with the jetpacks of the year 2000, we were promised magical CASE tools that would handle the details. That fizzled out. Instead XML just became a means for encoding configuration that people typed in by hand, sometimes aided by a crappy intellisense-guided schema. We all grew to hate it.
CSS was a great idea on the surface. Compact, not too complex looking: hook into elements by type, class or id, and style them as needed. But for many years it was a half-measure. Browsers behaved differently, and layout was counter-intuitive.
And THAT is what I just can't understand. We had models for how layout on user interfaces should work for many years on desktop applications. CSS just didn't care, it was poor for newspaper-like layout and poor for web-app layout.
CSS grid is such a refreshing step in the right direction, but why so long in coming?
And anyway, how long did we have to use browsers before people realized it's not exactly a piece of A5 paper?
\hspace*{0.75cm}