We should stop thinking in terms of "tech companies" and think of them in terms of "companies that use tech with a high degree of success". Ultimately any company that makes money is not a tech company because pure technology on its own does not make a business. Also, with the right incentives and management it is possible, although hard, for legacy companies to start using tech better to compete.
How many "non-tech companies" are non-tech companies simply because they're too disfunctional to use technology effectively? Think of your bank with its shitty password rules, only offering 2FA using SMS, and no useful APIs; that's a non-tech company. They either aren't aware of their lackluster technology, or are unable to organize themselves well enough to improve it.