Thanks for sharing your experience Tom. What a journey!
I have also dabbled in DIY while going to electronic school and then working in electronics. Read a few books, designed and built my own speakers. Friends heard them, asked for the same. Done. One pair is still in use today. It was fun but obviously nowhere near the level of the cabinetry, quality of drivers or design of today's speakers. But they sounded pretty damn good with decent drivers. Madisound and Parts Express had great cabinets and drivers from various manufacturers as well as all the acoustic stuffing and everything else one needed for a speaker build.
Also built a few primitive headphone amps. Mostly on breadboards but a few in a case. Can't say I enjoyed the results as much. Cheap solid state sounds very sterile. So I never got around to building a speaker amp but may still do that for fun these days. There are nice kits out there.
As to the main point, I have also gone through phases where gear came and went but failed to engage. Some moves were a waste of money, others did not cost anything since bought and sold preowned. Can't say I learned much from the experience other than a "different presentation" is often just that, a different presentation. Still no clue as to how to gauge what is actually better since it is all subjective and so vague.
Magazine reviews are designed to funnel the story to a happy end and an obvious conclusion. That is not reality IMHO. However, having lots of exposure to different gear sure does give one a good understanding of the type of sound one prefers. In the end, I think that is way more important than any standard, definition or a stereotype gear brands are known or being reviewed positively and enthusiastically for obvious reasons.
At this point, I can honestly say I have no plans. Just listening to a whole bunch of music, discovering new performers daily, falling in love with stuff I used to like all over again, being less impressed or moved with others... Perhaps not having a plan is also a testament to being in a good place with a hobby.