Just a thought, and relevant to this forum, that there is another area of interest relating to vintage radio. That is of home construction. Making new radios etc from old or new parts to a vintage design. This has been well represented in the Bulletin, the peak of genius being 'project of a lifetime', with numerous other projects for things like pantry transmitters or aerials.
I am most attracted to earlier, 1920's sets, and before, but my budget does not run to the valuable and rare. So I tinker with home constructed designs, old and new. What I am saying is that scarcity and high value does not relate to my interest in that period.
I believe vintage home construction will always attract some interest, and there are several websites attesting to the fact. Eg, the excellent
https://makearadio.com/index.php
So long as components are available I doubt the advancement of time will mean interest will be lost in any era. Even then there may be ways around that. Transistors, IC's etc, will have their own followers too. We just need to include them as they become vintage.