Why doesn't text adaptation work?

Question

css

I know about such a chip as

<meta name="viewport" content="width=device-width, initial-scale=1">

But initially I started to typeset without it, and now when you connect the tag on a mobile device, everything turns into a mess.
Is it possible to make responsive text without the help of window width calculation? Tried em ,rem,vh and wh, nothing works. It's funny that in the previous project I didn't use this tag either, but set the size as a percentage kmkrider.beget.tech/newconst.html , here's a link to that project.
And in the current