So it is with tech. On some level all companies are tech companies in that you need a website, Intranet, database, etc. These are all commodities though. A "tech company" is one where your tech is so good that either you can offer differentiated consumer experiences that nobody else can offer (eg. YouTube, Apple, FB's various products, consumer parts of Google) or people pay you to handle the tech things for them (eg. AWS, Microsoft, Google Cloud).
It’s a decent definition. It has some implications though
Almost no companies really differentiate via tech that nobody else can offer
Almost no game or app companies meet that bar. Most game companies have tech that another company can reproduce for example. Almost all apps use fairly commonplace tech.
There's a pattern there: Unity, Roblox, Unreal, Crytek, and Epic all build platforms and game engines used by other game developers, so again, you are what you do well enough to sell to people who don't want to deal with it.
By similar definitions, aren’t almost all companies also money companies, employee companies, legal compliance companies, strategy companies, marketing companies, mission statement companies, fundraising companies, etc?
That sort of definition works for giving job applicants a hint about whether the company might need them I guess.