It's hard to build an oscillator

It's great to do experimentation because you get to learn a lot, but at the end of the day stick with well-studied designs if you're making a something you want to use. The oscillators mentioned below all have well known strengths and weaknesses:

The author mentions that they consider a center-tapped inductor to be "fancy," but if you consider a regular inductor to be fair game, then the Colpitts oscillator is a good choice. And I suppose you could build a Hartley oscillator with two inductors rather than one center-tapped inductor.

If you consider op-amps to be fair game even though it is made from multiple transistors, then you might consider digital logic to also be fair game and should consider a Pierce oscillator. I'm also assuming that a crystal is also fair game, but those are quite cheap.

Side note- these oscillators are all part of the exam material for the Extra class amateur radio license in the USA. If you find lcamtuf's Substack interesting, then amateur radio might be for you.