My interest in SSTV started when I was around 15-16, there was an article about SSTV in an issue of 'Electronics Australia'. I was fascinated by the idea of sending pictures over a voice circuit, SW, VHF or even via a phone. That fascination has never left me.
As for staying with the B&W 8-second format, I guess it's similar to those in the UK who still dabble with 405-line television:-
https://www.bvws.org.uk/405alive/Also in Europe where you'll find 441-lines and quite a few others.
I agree on the higher-res and colour modes, I find them not as interesting, as you say you may as well send a jpg over the internet - though the same could be said about any SSTV mode. But it's origins are rooted in radio communications, you could say RTTY is the radio-based precursor to a text e-mail.
Steve A.