The higher the percentage the more of a "tech" company you are - the lower the more "traditional" you are.
No company will ever be 100% - all companies have other assets that are worth money and even a company that sells software as its main product might have lots of value tied up in their brand or their sales book of business.
Texas Instruments' value is mostly in their integrated circuits IP (as well as manufacturing prowess, process knowledge, and a little bit of software). They're still solidly a "tech" company in my books.
For example, imagine a company with very little proprietary code because they focus entirely on renting out their CPU/GPU/disk capacity, for supercomputing, databases, render-farms, cloud backup, etc. I'd still call that a "tech company."
It's also not clear how this "intellectual property of the source code" angle would accommodate the network-effects or value of a subscriber-base... Well, I suppose you could argue that such an asset doesn't require high-tech means, it could all be snail-mail.
An X business is one that differentiates itself on factor X. If they use it in a truly innovative way (which changes — what was innovative in the 90s is commodity today) or develop new technologies in house than you’re a tech business.
Meta and Amazon are businesses that depend on developing technology (so are true tech companies as much as NVIDIA or Apple) but nowadays “tech” merely means at best “online”. Most so-called “tech” companies don’t actually develop any technology at all, often being less technical than a non-“tech” company like, say, State Farm.
The term has become so denatured that a new term, “deep tech” has been coined to mean what “technology company” used to mean.