You're essentially asking the Billion dollar Question.....What is the Future?
Trading off support lines...a roller coaster or mountain range.....when it goes up, bet down.....when it goes down within a range, bet up.
BOOM. Become a Millionaire automatically for Everyone. YAY
That is of course false logic. It only works and sounds great, awesome, in hindsight in a book or video trading course for only $995, or special VIP couching for a weekend of $6,995.
Everything works in trading, until the market decides it hates your great, magical, trading system and dumb self.
I can only speak from a day trader's perspective, but it helps to establish a reasonable, general, loose, market hypothesis for the day. and wait for tells and signs of when to strike, when to place that trade....then from that point...just patiently sit back and watch the market, ....deviations can occur, so F what you generally know about Support/Resistance lines, and trading can be part art, part science,
Are you saying they have no value?